The operational activities conducted in a shipyard are exposed to high risk associated with human factors. To investigate human factors involved in shipyard operational accidents, a double-nested model was proposed in the present study. The modified human factor analysis classification system (HFACS) was applied to identify the human factors involved in the accidents, the results of which were then converted into diverse components of a fault tree and, as a result, a single-level nested model was established. For the development of a double-nested model, the structured fault tree was mapped into a Bayesian network (BN), which can be simulated with the obtained prior probabilities of parent nodes and the conditional probability table by fuzzy theory and expert elicitation. Finally, the developed BN model is simulated for various scenarios to analyze the identified human factors by means of structural analysis, path dependencies and sensitivity analysis. The general interpretation of these analysis verify the effectiveness of the proposed methodology to evaluate the human factor risks involved in operational accidents in a shipyard. Increasing concern about various risks involved in shipyards, especially the risks that are human-related, can be observed ,2. Many A lot of studies have been undertaken to identify and evaluate various causes contributing to the occurrence of accidents in shipyards. Jacinto and Silva  studied Identification of critical risk events involved in the shipyard operation is an effective way to prevent accidents in shipyards. When identifying the hazardous events or critical risk events involved in shipyard operations, the factors to take into consideration have been proposed by International Labor Organization (ILO) . The queThe causes for accidents and critical risk events in shipyard are mainly attributed to aspects of adverse environments and human-related and/or organizational factors. The environmental factors generally include various conditions on site, such as weather, atmosphere, available hardware or technical equipment in shipyards. Celebi et al.  identifiHowever, human-related factors involved in shipyard accidents have not been investigated systematically. Even though the importance of human-related factors contributing to shipyard accidents is recognized by many scholars, such as Barlas and Izci , Efe 2]2] and CrA double-nested model for the assessment of human-related risks is proposed by mapping a fuzzy fault tree into a Bayesian network based on HFACS.The difficulty of obtaining the conditional probability table of Bayesian network is overcome by canonical probabilistic models.Mutual information is introduced to identify main paths of risk propagation.The focus of this study is to establish a double-nested accident analysis and risk assessment framework, under which the fuzzy algorithm and information theory are integrated to quantify and address the uncertainty of human factors and their dependency in shipyard accidents. Moreover, an accident that occurred in a Chinese shipyard is used as a case to verify the proposed methodology. Based on a modified framework of HFACS, the combination of FTA and a fuzzy extent Analytic Hierarchy Process (AHP) is utilized to systematically establish the causal relationship of accidents and address the randomness of risk factors in this study. In addition, BN is adopted to predict the probability of risk because of its powerful learning and reasoning capability. In particular, the introduction of canonical probabilistic models reduces the difficulty of obtaining the conditional probability among nodes in the Bayesian network, and it can deal with the complexity involved in human factors analysis. The model developed in this study can help to address human-related risks in shipbuilding and repair projects from a system perspective, and reduce the incidence of occupational accidents and injuries. The salient features of the proposed methodology are listed as follows:The rest of this paper is organized as follows: A complete accident analysis should not only investigate the direct cause of an accident but also identify the deep-seated human risk factors hidden in the system to fundamentally eliminate the latent hazards. For this purpose, the fuzzy fault tree model, which is nested with the hierarchical framework of the HFACS, is first proposed to thoroughly analyze the human factors that contribute to occupational accidents in the shipbuilding and repair industry. Then, it is mapped into BN, which is the double-nested model proposed in this paper, to further explore the characteristics and mechanisms of human factors quantitatively through probabilistic reasoning and uncertainty and sensitivity analysis. The specific schematic diagram is shown in HFACS was initially proposed based on the ‘Swiss cheese’ model to analyze the human errors that led to the repeated occurrence of naval aviation accidents in a systematic manner , and it In the category of ‘preconditions for unsafe acts (UP)’, one of its subcategories, personnel factors, including personal readiness and crew resource management, has been removed. The ‘crew resource management’ which refers to a series of communication and team cooperation issues that affect personal performance is considered under ‘resource management’ because it is closer to the concept of human resource management, and ‘personal readiness’ is integrated into the ‘conditions of operators’ for discussion.In the category of ‘unsafe supervision (US)’, ‘failure to correct known problems’, is related to the situation in which vulnerabilities related to personnel, equipment, etc., are known by supervisors and allowed to continue uncorrected. It is replaced by ‘inadequate process supervision in emergency management’. In most cases, the meaning of ‘failure to correct known problems’ may overlap and cross with the content of ‘inadequate supervision’ and ‘supervision violations’ because there is no restrictive characterization of it.HFACS is frequently applied to investigate and analyze the causes of accidents in various industries. Overall, most categories of the original HFACS framework are retained, while some minor optimizations are implemented to better meet the needs of a particular research field . The modSince it is difficult to obtain quantitative and complete data on human behavior due to its subjectivity and randomness, the quantification of human risk factors often depends on expert judgment. The AHP proposed by Saaty  is widelFault Tree Analysis (FTA) is one of the classical methods for accident analysis in complex systems. Taking the system failure  as a premise, probable causes can be deductively determined and divided into branch or tip nodes of the fault tree model. The nodes that cannot be decomposed further are basic events (BEs), and the others are intermediate events (IEs). Top event (TE) in the fault tree model refers to the specified accident scenario. Consideration of the logical correlation among events, different logic gates are introduced to express the diverse properties of causal relationships in accidents, and the cause–consequence relationship can be visualized as a tree graph. According to FTA, not only will the direct causes of accidents be investigated, but all the accident causes, including potential risks, will also be found . TherefoIn the qualitative part of FTA, the Boolean algebra reduction method is utilized to determine the minimal cut sets (MCSs) and minimal path sets (MPSs). MCSs represent accident modes, and the greater the number of MCS, the more dangerous the system is. Conversely, MPSs reflect the safe performance of the system. For quantitative FTA, the first step is to calculate the failure probability of BEs, and then, the failure probability of TE can be computed for risk assessment. In the present study, FTA is developed by converting the human factors identified under the HFACS framework into corresponding elements of the fault tree and is mainly utilized for in-depth causality analysis of accidents and identification of MCSs and MPSs.The Bayesian Network (BN) is a multi-element graphical network based on probability and uncertainty. It has been widely used in risk analysis field because of advantages in knowledge representation, autonomous learning, inference and prediction for incomplete information . A givenevidence. In general, the query set could be a combination of variables or contain just one variable. In addition, evidence is usually given in the form of accidents, incidents, near misses, etc. [The most prominent function of a BN is diagnostic reasoning. Based on Bayes’ theorem, the prior probabilities of a query set es, etc. .(2)P’ are at the bottom of the HFACS framework, which are the active factors and the most direct causes of accidents. According to ‘The Classification Standard for Casualty Accidents of Enterprise Employees’ , these iThe second layer is ‘Preconditions for unsafe acts (UP)’ containing two categories: conditions of operators and environmental factors. According to the domino theory, unsafe acts of human and unsafe states of machinery are the direct causes of accidents . The env‘Unsafe supervision (US)’ is the indirect cause of accidents at the management level, which consists of inadequate supervision, planned inappropriate operation, inadequate process supervision in emergency response, and supervisory violations. Inadequate supervision reflects the extent to which supervisors perform safety management responsibilities, including the supervision and management of personnel and resources. Planned inappropriate operation refers to the management and assignment of work, including risk management, operator matching, and setting work schedules. Inadequate process supervision in emergency response is especially concerned with the timely prevention and correction of unsafe behaviors in the process of emergency response. In addition, supervisory violations are generally focused on the on-site management.‘Organizational influences (OI)’ are also the hidden causes that lead to accidents. Such defects may not have a direct impact, but they are likely to cause hazards under the combined effect of other factors. This category consists of three types: resource management, the organizational climate, and the organizational process. In this study, resource management takes the perspective of human resource management. The organizational climate is an invisible risk factor that has a subtle impact on human actions. In addition, the organizational process is the response to the operation of the safety management system, and it can test the stability of the system.In this section, the proposed HFACS is used to analyze the explicit and implicit causes leading to the occurrence of the example accident used by identifying human factors at each layer and in each category. To identify all human factors in the accident scenario described, expert experience, a literature review, accident investigation and case analysis are combined and applied. After safety meetings, a questionnaire survey, and literature review, the risk elements associated with human factors are summarized in As proposed in n = 13), preconditions for unsafe acts (n = 9), unsafe supervision (n = 5) and organizational influences (n = 4). All human-related risk factors and their symbols and descriptions are shown in In addition, expert knowledge is introduced as an important supplement. One way is to supplement and adjust human factors by obtaining this knowledge through questionnaire surveys and interviews to improve the comprehensiveness and representativeness of the identified elements. Furthermore, by organizing symposiums, the scientific and rational classification of risk factors will be unanimously recognized by experts. 31 human factors were ultimately identified and divided into four groups: unsafe acts , ‘Organizational climate’ (OC) and ‘Organizational process’ (OP) all have the possibility of leading to the TE, so OR gates are set between the TE and the three primary IEs. By analogy to BEs with the same method, a causality diagram of the fault tree is constructed, as shown in The quantitative analysis of the FTA would be conducted in the present section. The fuzzy extended AHP is introduced to compute the failure possibilities of BEs. Five non-homogenous experts are firstly invited to make independent judgments on the contribution of risk factors, and triangular fuzzy numbers are used to make judgments intuitively. The basic information for these five experts can be found in Let Consider two triangular fuzzy numbers Then, the fuzzy extent AHP is introduced to obtain the failure rate of human factors. Expert credibility has been added to the process to reduce both empirical limitations and subjective bias. In practice, because of the comprehensive effect of the personal knowledge background, work experience and so on, the reference weights of expert opinions on a certain issue are not equal. Nevertheless, whether the expert evaluation is scientific or not, it has a direct impact on the results of the study. Professional position, length of service, education level and job title .As shown in Let With The algorithm of the fuzzy extent AHP is as follows:Step 1: Development of fuzzy reciprocal judgment matrix. Set Step 2: Determination of the fuzzy synthetic extent value. Applying the extent analysis method, the comprehensive fuzzy value To obtain Step 3: Apply the fuzzy number comparison rule, and calculate the degree of possibility of To compare Step 4: By standardizing the above weights, the standard values Step 5: Calculate the integrated values All BEs in the fuzzy fault tree are considered as parent nodes in the BN, and all IEs are regarded as child nodes.The nodes in the BN are connected according to the relationship between various layers of events in the fuzzy fault tree, and the direction of edges is consistent with the cause–consequence relationship in the fuzzy fault tree.The failure probability of each BE is directly assigned to the corresponding parent node in the BN as its prior probability distribution.The conditional probabilities of each variable, i.e., the CPT, provide the functional extension of logic gates in the fuzzy fault tree.To map the fuzzy fault tree into BN, the transformation relationship between the corresponding components needs to be established. According to the logical relationship expressed by fuzzy fault tree and its representation in BN, the transformation from fuzzy fault tree to BN is presented as follows:As mentioned before, the prior probability distribution for nodes without parents also corresponds to the failure probability of BEs. The fuzzy extent AHP in Then, by filling out the questionnaire of indicator evaluation, five experts made their pairwise judgment results on the failure possibility of human factors at different levels. Fuzzy evaluation given by the expert group is shown in The above values are standardized and integrated with the influence degree of the upper-level indicators, and the calculation results are as follows:Ultimately, the probability of each identified human factor is calculated. To convert the impact weight of human factors (crisp failure possibility) into failure probability, the approach proposed by Onisawa  is emploFalse is 100%, the result of the Noisy-OR gate is considered to meet the scientific criteria of the study, and the leaky Noisy-OR gate is no longer used. Meanwhile, the leaky probability For nodes with parent nodes , prior probabilities can be acquired through the forward reasoning function of the BN, in which the calculation of the conditional probability is critical. As mentioned in The failure probability of each human factor calculated in There are 33 MCSs, approximately twice as many as MPSs. Each MCS contains a small number of BEs. Since the MCS with fewer events is more likely to cause the system failure than the MCS with more events, the state of this system is unstable and the probability of accident occurrence is higher.Regarding the MCSs that contain only one BE, it can be found that the BEs all belong to the category of ‘Violations’. In addition, ‘Environmental factors’ only appear in the MCSs composed of multiple BEs, that is to say, they cannot lead to system failure independently. Therefore, ‘Violations’ are more likely to cause accidents than ‘Environmental factors’. That is, comparison of the unsafe behavior of humans and the unsafe state of machinery and materials, the former contributes more to accidents.There are 17 MPSs, among which four MPSs contain 13 BEs (the largest number of BEs). Generally, the more BEs contained in an MPS, the more complex the technical problems in the system, and more resources are required to ensure the TE does not occur. Therefore, the MPSs consisting of a larger number of BEs are considered to be weak links that easily cause system failure.The purpose of structural analysis of static fault tree is to explore the rules of system failure due to common causes. As mentioned in Bidirectional reasoning and probabilistic prediction can be realized in a BN by information updates on evidence, which is called evidence propagation . The obsConsidering a discrete random variable Considering two random variables Since conditional entropy measures the uncertainty contained in In this accident scenario, M1 is selected as the target variable, and X1, X5, X11 as the known evidence variables respectively. The corresponding value of entropy and dependence is shown in RoC) is considered to be more important [The key factors influencing the occurrence of accidents can be inferred through backward propagation of BN with the Pareto principle, which is helpful for the precision management of risk sources. In this study, the sensitivity analysis is incorporated to achieve this purpose. Under specified conditions, the relative importance of the independent variable to the specific dependent variable is calculated by Equation (26). A risk factor with a higher ratio of change (mportant .(26)RoCFalse. Then, the sensitivity of factors can be quantified according to Equation (26), and the results are shown in RoC are 1.2266, 1.1882 and 1.1111, respectively. They are considered the main causes of the accident, and OP has the largest contribution among them. Additionally, we set the states of ‘Accident’ and ‘OP’ to False and observe the change of their parent nodes, i.e., ‘Lax daily safety management and inspection (M4)’, ‘Unreasonable ship repair plan (M6)’, ‘Inadequate guidelines in emergency rescue (M7)’, and ‘Inadequate on-site control (M8)’. Then, the values of RoC for these nodes are calculated as 0.5520, 0.5259, 0.3520, and 0.5350, which reflects the fact that daily safety inspection and supervision are particularly important for accident prevention.In the developed BN, the failure probabilities of all identified human factors are updated to posterior probabilities by setting the state of ‘Accident’ to The three factors with sensitivity slightly less than ‘Organizational influences’ are ‘Lack of team communication and cooperation (M10)’, ‘Operating errors (X3)’, and ‘Rescue without plan (X7)’. This indicates that personnel involved in shipyard operations, such as the operators of engines, electricians, dock repair workers, comprehensive workshop operators, and production supervisors, should pay attention to coordination and cooperation with the members of the organization, and workers should always be careful to avoid mistakes during operation. In addition, we calculate the cumulative percentage of the causes of accidents other than ‘Organizational influence’. As shown in In this study, a double-nested model that integrates the superiorities of HFACS, fuzzy fault tree and BN is proposed for comprehensive risk assessment and path dependence analysis. The hierarchical characteristic of the HFACS is firstly utilized for potential risk identification and classification. In particular, not only is the classification of risks implemented at different levels of the HFACS but also the risks are divided into direct and indirect causes of accidents. Then, the elements of HFACS are transformed to corresponding BEs and IEs in the fault tree to systematically represent causal associations under specific accident scenarios. A fuzzy fault tree is developed with the application of fuzzy extent AHP to calculate the probabilities of BEs, which is further mapped into a BN to expand the bidirectional propagation function and uncertainty and sensitivity analysis. In addition, an equivalent CPT of nodes with multiple parents in the BN is generated by introducing canonical probabilistic models, namely, the Noisy-OR gate and leaky Noisy-OR gate. Finally, the methodology was applied to a suffocation accident that occurred in a shipyard.In general, the double-nested model developed in this paper has the functions of perception, inference, and prediction. Through the empirical application of the aforementioned model for a case accident, the safe or failure state of the production system under different combinations of human factors is discussed. It vividly reflects the significant distinction between the combination of risk factors and the sequence of risk failures, which is also one of the functional differences between FFT and BN. After that, the dependence paths between risk factors are analyzed by combining the information theory with the forward propagation function of the BN to demonstrate the regular pattern of risk propagation. In these path dependencies, organizations that are experiencing failure are prone to further failure and the threat of potential occupational accidents. In addition, backward propagation combined with sensitivity analysis is performed to identify key human factors. The output of the model is consistent with the actual situation, and risk factors not investigated in the accident report are also identified and discussed. The research results could provide a reference for further improvement in industrial accident prevention and safety management from two aspects: one is to eliminate the hidden dangers of accidents, and the other is to control the adverse evolution of accidents.


We construct the first consistent series on the long-term distribution of income in Poland by combining tax, household survey and national accounts data. We document a U-shaped evolution of inequalities from the end of the nineteenth century until today: (1) inequality was high before WWII; (2) abruptly fell after the introduction of communism in 1947 and stagnated at low levels during the whole communist period; (3) experienced a sharp rise with the return to capitalism in 1989. We find that official survey-based measures strongly under-estimate the rise in inequality since 1989. Our results highlight the prominent role of capital income in driving the U-shaped evolution of top income shares. The unique inequality history of Poland speaks to the central role of institutions and policies in shaping inequality in the long run.The online version contains supplementary material available at 10.1007/s10887-021-09190-1. Our understanding of the evolution of inequality and its determinants depends on the available empirical evidence. As we have obtained new evidence, charting inequality further back in time, the old paradigms have been challenged and new ones developed  from combined tax and survey data. Figure 015 from 6The highest increase took place immediately at the onset of the transition in the early 1990s and was induced both by the rise of top labour and capital incomes. However, the strong rise in inequality in the 2000s, after Poland joined the European Union, was driven solely by the increase in top capital incomes, which are dominant sources of income for the top percentile group. Today, Polish top income shares are at the level of most unequal European countries, most notably Germany and the United Kingdom, but still substantially below those documented in Russia . Our series also shed new light on the role of inequality for growth in Poland and other post-communist countries. We highlight several ways in which institutional systems have mattered regarding the way inequality affected development through accumulation and efficiency channels.The paper is organised as follows. Section This paper lies at the intersection of different strands of literature looking at the interplay between inequality and growth. In what follows, we present those theoretical strands through the lens of Polish distributional history.This paper shows the evolution of inequality in Poland in the long run and its determinants. Here our work directly builds on the top income literature. Kuznets  first co7Economists have generally discussed the distributional impact of growth through the distributional effects of factor accumulation and technical change  factor accumulation , and ii) efficiency in using factors and technology Weil, , ch.13.112Factor accumulation channel. The ‘classical’ approach posits that inequality is beneficial for economic growth as it shifts resources to rich individuals, who have higher marginal propensity to save, thereby leading to higher aggregate savings and higher physical capital accumulation, and hence growth . However, due to comprehensive nationalization of the means of production, the positive effects of inequality on aggregate saving operated through a more pronounced functional, rather than personal, inequality.The fall of communism and the transition to a market economy amplified the complexity of the inequality-growth nexus, entailing a change in the relative returns and the way inequality affects growth. Lower inequality at the outset of the transition, with binding credit constraints, was conducive to the large expansion of tertiary education documented, which has been critical for the country to successfully adapt to the global environment and to approach the technological frontier  guidelines  and Austrian Empires (1898) during the Partitions of Poland. Both Prussian and Austrian income tax statistics provide tabulations of income taxpayers in a regional breakdown, which has allowed us to construct top income shares for provinces with significant Polish population . There is no tax data for the Russian Partition (the Congress Kingdom), as comprehensive income tax was never introduced in Imperial Russia.fundowany) and earned income (niefundowany), organised by a large number of income brackets containing the number of taxpayers in each bracket and their corresponding tax obligation.In 1924, the newly independent Poland introduced a unified progressive income tax for its whole territory. Detailed interwar income tax statistics were published separately for unearned income . The tax administration has published annual income tax tabulations since 1992. Tabulations are organised by income ranges that correspond to tax brackets as defined by the progressive tax schedule, with each bracket containing the number of taxpayers, their total income, deductions and the corresponding tax obligation. Due to the limited progressive structure of Polish PIT, the number of brackets in published statistics has been relatively small , with more than 90% of taxpayers located in the bottom bracket. As a result, although a great majority of the population is subject to PIT, the available income tax tabulations cannot be used to recover the entire income distribution. Instead, we use information on high-income taxpayers in combination with the household survey data.Household income surveys. A Household Budget Survey (HBS) has been regularly conducted in Poland since 1957. Until 1972, it covered only employees in the socialized sector, excluding agriculture. Thereafter, it was conducted for four types of households: worker, mixed, farmer, and pensioner households  data from Atkinson and Micklewright . For the interwar period we rely on historical series published by Kalecki and Landau  between these percentiles.21The general methodology we use to combine survey and fiscal data consists of two basic steps. In the first step we use the raw survey tabulations and generalized Pareto interpolation techniques , it is reasonable to assume that eligible high-income taxpayers file a joint declaration by equally splitting their income in order to reduce their tax obligation. According to the PIT reports, the majority of eligible taxpayers used the joint taxation.A further issue is that the homogeneity over time can be impaired by changes in the tax unit in the tax code. While the data for the communist and post-communist period relates to individual units, the tax unit in Austria, Prussia, and in interwar Poland was the household, with the total income of household members ascribed to the head of the household.Definition of Income. We focus on the distribution of pre-tax income, which refers to the sum of all income flows going to labour and capital, plus pensions but before other taxes and transfers. This income concept corresponds to the concept of fiscal income reported in the income tax statistics . A major difference is due to the fact that the national income includes in addition tax-exempt capital income, such as undistributed corporate profits or imputed homeowners’ rents. We do not impute these items due to data availability, but, in general, it has been found that the fiscal correction (using income tax data) accounts for the bulk of upward correction of raw survey inequality, and further adjustment for the distribution of tax-exempt capital income has been shown to be of limited importance  was economically the least developed of the three ‘partitioned’ Polish regions.The positive relationship between inequality and growth may be postulated both for Austrian and Russian industrialization Table . Conceiv30The unification of Poland in 1918 is one of the pivotal events in Polish history. Poland was established on the world map after 123 years under foreign dominions. However, this century-long dream had to be realised in quite a tumultuous atmosphere of economic crisis, broken international trade, and recovery from the massive destruction and human losses of the Great War.Our starting point in the interwar period 1924) coincides with the lowest documented point in top income shares during the existence of interwar Poland, with the share of the top percentile slightly above 8% . Accordingly, it is plausible that this development indicates a deteriorating position of Polish farmers relative to other social groups. Almost two-thirds of the population was made of small farmers and it was agriculture that was most adversely affected by the Great Depression, in the first place due to a strong fall in agricultural prices Landau, . In contThe Great Depression led to a differential income fall for different top groups see Fig. . The topFurther insights could be obtained by looking at the spatial distribution of county-level top income shares in Poland.In theory, the distribution of income under a socialist state should be based on the rule “from each according to his ability, to each according to his labour” , even the majority of small shops and crafts were nationalised. The next decisive episode was the currency reform in 1950 that virtually confiscated all personal financial wealth.However, a decline in top concentration also ensued as communists strengthened their rule in the country, which led to an almost complete expropriation of capital income by the state.As a result, labour income and the wage setting process become the main determinants of the interpersonal income distribution in a socialist society. Indeed, Atkinson and Micklewright , p. 128 Figure Kalecki  and BeskThe Communist government used institutional factors, such as unionisation or centrally determined wages and prices, to control real wages. During the early years of communism, exceptional power was given to the high-level managers, which increased within-firm wage dispersion Brus, . PopularLow labour productivity was a plague of the socialist economy in the 1960s , subsided over time . However, this growth has not been equally shared. Table In this section, we discuss  the most important forces driving the rise of inequality after 1989. The ‘return’ to a market economy may be seen as a reversal of the process of communist equalisation, manifested in comprehensive labour market liberalization and the privatization process. Economic forces consequently assumed a more important role in determining inequality, yet their distributional impact was critically mediated in a complex interaction with the specific institutional and political context. We show that a technology-driven demand for an educated workforce and globalisation contributed to the growing earning and income inequalities. However, an even stronger rise in inequality during the transition was precluded by extensive social transfers, higher minimum wage or more gradual privatization.Rising earnings dispersion has been commonly identified as the main cause of rising income inequality in Central Eastern European countries during the first years of transition  from the early 1990s until 2015. Next, we regress income shares  on minimum to average wage ratio or the EBRD privatization indicator, and a set of country fixed effects and year fixed effects, which together capture all country-specific time-invariant determinants of inequality and all common annual shocks to income shares. Figure The recent rise in inequality in Poland has been driven again by the increase in top income shares. The top 10 percent share has steadily increased since the early 2000s and reached levels of around 35% by 2015 Fig. ,55 but iceteris paribus, the rise of capital share in Poland would imply the rise of top 1% by 1.4 pp and the fall of all other income groups.A robust rise in top business incomes after 2004 was the main reason behind the structural rise in top income shares.The rise of capital share has often been attributed to the new globalization phase and increasing participation in international trade. We point to three broad channels concerning how globalization might have potentially induced the rising capital share in Poland.The distributional effects of globalization and technological change can also explain a decline in the income share of the middle 40% Fig. , which cWe next turn to international comparisons. First, we compare the long-run evolution of income inequality in Poland and Western European countries. Figure While inequality stood at low levels in all countries in the three post-WW2 decades, the introduction of communism dramatically reduced top income shares in Poland and kept them below the levels observed in western European countries. With the fall of communism, the top percentile share substantially increased in Poland between 1989 and 2015, to reach the levels characteristic for more unequal European countries, notably Germany and the UK, and placed Poland significantly above estimates for the group of Continental, Nordic and Southern European countries  as determinants of inequality but argue that their distributional impact depended on a wider country-specific institutional and socio-political context. These processes have also recently contributed to the growing importance of capital in the economy, suggesting that the future of inequalities in Poland is likely to be linked with the prominent role of capital income at the top. Yet, our paper shows that these trends are not inevitable and the future inequality dynamics in Poland will crucially depend on institutional and policy choices.Rising income inequality in Poland has important political and social implications. It shows that the official numbers on the average GDP growth might have little in common with the actual lived experience of most people. Those “left behind” are often missing from the public discourse, which further fuels the illusion of inclusive growth and limits the demand for social policies. As a result, inequality stands today at the heart of the democratic debate in Poland and worldwide, which is evident in the recent populist backlash in Poland and internationally. The issue of distribution of gains from economic growth has thus become crucial for sustaining the long-run development. We hope that our work will be a contribution to how to approach these imminent challenges.Finally, this paper shows promising avenues for future research. Most importantly, our work presents the central building block for constructing comprehensive Distributional National Accounts for Poland Below is the link to the electronic supplementary material.


In the age of digitalization, social media has played a significant role in quickly spreading the news about current affairs. From December 2019 to now, coronavirus disease 2019 (COVID-19), with its several mutated shapes, has more transmissible potential catastrophe and has become a severe phenomenon issue worldwide. The international spread of the epidemic has created fear among people, especially employees working physically in different organizations. The present research aimed to measure the impact of social media on its users in the China. The social media users more often were influenced by shocking news instructively and destructively. The research analysis was based on service sector employees and data collected from 630 respondents via a structured questionnaire. This research was confirmed the negative impact of fear on social media on the performance of employees. This research was also confirmed the moderation impact of the COVID-19 vaccine on the relationship between social media fear and employee performance. This research recommends that the China Censor Board checked the news and its validity to reduce the fear of COVID-19 among employees. This research will become a roadmap for organizations and media controllers to understand the impact of social media during an intense situation. The telecommunication sector will reduce psychological disease and enhance the work capability of employees by controlling unnecessary and unapproved material about sensitive issues. The recent study initiatives, emphases of China media, and self-reporting social media are increasing fear and melancholy due to the outbreak of novel coronavirus disease 2019 (COVID-19) worldwide. Media plays an essential role in spreading awareness for some currently occurring issues, such as COVID-19, which is becoming the source of disease spread worldwide . COVID-1Providing accurate information and aiding knowledge among social media of citizens is called upon to take responsibility. Furthermore, it has been distinguished that the publication of misleading information on social media networks, where almost all media channels are exposed to diseases, has harmful effects on general public health and mental health . Victor In the same way, Studies show that the fear of an illness and any resulting behavioral changes may be passed on through a virus . There aThis research aims to measure the impact of social media on the performance of employees of industries during COVID-19. This research also identifies the toxicities of speech freedom about the pandemic and curbing dissenting political views on social media. The commoner does not know about the facts and figures for a specific situation. When an individual speaks out in an extreme case, one presents their mental state and psychological effect on the reader. The pandemic phenomenon reflects health issues other than a pandemic, which reduces the performance levels of employees. This overreach is destined to evoke an intense reaction and severe to alienate the general public from its telecommunication approach at a time when a unified stance is essential.As a dependent variable in this study, the performance of the workers is taken into consideration. It is the performance of workers in an industry that industrialists are most concerned about since the profit or loss of a sector is directly linked to the performance of employees. The outbreak of COVID-19 had a significant impact on employee performance in a variety of ways, such as lockdown, frightening news about the pandemic, limited working locations, and stringent operating procedures, among others. The basic rationale for selecting this variable is real, as the success of the industries and the performance of the workers are very complementary to one another. Because the economy is in such bad shape, the luckiest individuals are included among those working . The perIn late December 2019, when China reported a mysterious illness in Wuhan city called COVID-19, some cases were registered due to this illness. The infection has spread around the world and has become a pandemic disease. The telecommunications institution plays an essential role in the awareness of people about the effects of the disease. Still, at the same time, media became a source of spreading fear and anxiety among their users. The social media platforms gave their users different instructions about preventing this virus, such as washing their hands, wearing the mask, and keeping distance among themselves , but at All developed and developing countries trying to cope with the epidemic and save the health of human beings should take essential preventive measures, such as lockdown, contact tracing patients, green health code, and quarantine . Until nAdditionally, Similarly, It seems that pleasure, anger, and worry are all socially infectious types of emotion. Research has shown that when it comes to strangers, especially the spread of negative emotions . IndividEven though most research on emotion contagion has focused on human interactions, a recent study has shown that digital communication may be a conduit for emotional contagion . The facH1: Social media fear significantly influences employee performance.H2: COVID-19 worry significantly influences employee performance.Workers are the foundation of any business, and the primary duty of any organization is to ensure that its workers are safe and secure, particularly during this difficult period of a pandemic outbreak. With the COVID-19 pandemic in full swing, it is clear that companies must take their responsibilities to safeguard workers seriously and that the widespread distribution of COVID-19 vaccinations is necessary to preserve their health even in the face of widespread vaccination reluctance. According to a recent study, businesses of all sizes must act responsibly to ensure that no harm is done, care for their employees, and allow the government to do its job in protecting people. Additionally, every company should make concentrated efforts to meet employee needs and desires cost-effectively to improve the performance of the company. Exposure of workers to COVID-19 may be reduced by providing safe and healthy working circumstances, such as appropriate protective equipment and training and personal hygiene practices, such as hand washing and coughing etiquettes. The first step is to gather current information about their situation . A varieThe vaccine of COVID-19 is used as a moderator variable between the performance of the employee, COVID-19 worry, and social media. The vaccine is performing two rules at a time in this research. First, it will point out the psychological impact on the employees of industries who are afraid of COVID-19 due to media. Second, it will also measure the effectiveness of vaccines because the immune system of the human body is related to mental health. The accurate effect of the vaccine is not only dependent on the vaccine but also characterized the vaccinated person. The psychological factors, i.e., stress, depression, and loneliness, which are created by exaggerating spreading fear by media, may affect the immune system of respondents. The vaccine of COVID-19 is the best moderator variable that can elaborate the intensity of the relationship between the dependent and independent variables. The inflammatory markers of vaccines rise within hours due to Innate Immune Response in normal human beings, but its effect and reaction period are prolonged for stressed people. Again, the fake news of social media restricted the general public from accepting the vaccine of COVID-19. The useful information and encouraging vaccine material are rare on social media than negative and discoursing materials . Hence, H3: COVID-19 vaccine moderates the relationship between social media fear and employee performance.H4: COVID-19 vaccine moderates the relationship between COVID-19 fear and employee performance.As per previous literature, most research is available on social media fear and COVID-19, but the performance of employees and vaccines are still undiscussed. In this section, the theoretical information is categorized for two purposes, i.e., an indication of previous research and direction and the current inclusion of this research work. The independent variable is explained in detail with cited references, but vaccine and employee performance have only declared the moderator and dependent variables due to unavailable literature.This study designed a questionnaire according to the hypotheses stated above. The participants in this study were experienced users of social media platforms in China. A self-administered questionnaire was used to collect data from respondents. The research analysis was based on service sector employees, and data were collected from 630 respondents via a structured questionnaire. A pilot study with 100 participants was carried out. Since providing recommendations, revisions were made to the final questionnaire to make it more understandable for the respondents of the study. To ensure the content validity of the measures, three academic management experts analyzed and made improvements in the items of constructs. The experts searched for spelling errors, grammatical errors, and ensured that the items were correct. The experts have proposed minor revisions to social media fear and employee performance items and advised that the original number of items be maintained. This study used an online community to invite social media users to complete the designated online questionnaire system. Online questionnaires have the following advantages : (1) samThe study used items established from prior research to confirm the reliability and validity of the measures. All items are evaluated through five-point Likert-type scales where “1” denotes strongly disagree, “3” denotes neutral, and “5” denotes strongly agree. We used 10 items adopted from a prior study by This study analyzed the data through the SPSS. Primary data were collected from 630 respondents, and demographic characteristics of the work position of respondents, such as age and gender, are illustrated in Data collection for this study was performed using a questionnaire. In this study, we analyzed the impact of social media fear on the performance of employees through the moderating role of the COVID-19 vaccine. Before testing the structural model, the measurement model was analyzed in terms of construct reliability, convergent validity, and discriminant validity. According to our assessment of the reliability of the indicators, there are 25 indicators with outer loading greater than 0.70 . A totalt-value is 2.093. Social media fear significantly impacts the COVID-19 vaccine, with a beta value of − 0.202 and 6.140. This confirms that the independent variable included in the model has a positive and significant impact on employee performance. Based on the t-value independent variable has a positive and significant impact on employee performance at p ≤ 0.05.Hypotheses show the influence of independent variables on employee performance. R2 and adjusted R2. The linear regression results have measured the proportion of variations in selected dependent variables toward independent variables with 0.867. The decreasing trend of Adjusted R2 indicated that the predictions would not improve more according to expectations.p < 0.00) which gives positive support for H1 of our study. The moderation hypotheses of the COVID-19 vaccine in the path between social media fear and employee performance (H2) are tested using the two-stage continuous moderation analysis , indicating the moderating effects are statistically significant at the 0.01 level. This supports H2 of this study. analysis . The modIn this study, we used a large sample of social media users; we tested the theory that employees who are more sensitive to emotion contagion would experience more anguish and display symptoms during the COVID-19 pandemic in China. Individuals with heightened fear, or who are more affected by the emotions of others, were more likely to have greater degrees of fear, sorrow, anxiety, and stress, according to COVID-19 results. These details are covered in more detail in the section below.Although the variations in sensitivity to COVID-19 worry and fear of social media were found to be small, generally, we observed that those with greater vulnerability to contagion were more likely to exhibit worry about the virus and maladaptive reactions . This result is consistent with other research, which showed that those with a greater capacity for emotional contagion tend to have a more pronounced stress reaction to stressful experiences . BecauseAdditionally, we examined the potential that general social media usage and media consumption regarding COVID-19, in particular, might be significant in predicting the degree of anxiety around COVID-19. Additionally, we examined the possibility that the COVID-19 vaccine might serve as a moderator in these interactions. Consumption of media regarding COVID-19 was shown to predict the degree of anxiety associated with COVID-19 significantly, but this connection was not reduced by emotion contagion. One previous study discovered that the degree of emotion contagion moderated the stress response following exposure to a traumatic film. Still, this study was conducted in the laboratory and used a highly controlled stressor, whereas our measure of media exposure on COVID-19 was retrospective and uncontrolled. As a result, it is conceivable that a substantial moderating effect might have developed under more controlled circumstances.As our further research showed, we discovered that the relationship between COVID-19 worry and fear of social media and employee performance was influenced by the COVID-19 vaccine, making it greater for an employee who was more susceptible to social media fear. The connection between social media fear and employee performance is likely exacerbated because of the increased susceptibility to infection with the virus that causes COVD-19. Despite this warning, it is important to remember that the study was based on the primary analysis of cross-sectional data, meaning no causal conclusions can be drawn. Further studies are also required to examine this in clinical populations.Study limitations must be considered while evaluating current findings. For our study, we first gathered all of our data online using a cross-sectional design, where subjects answered questions at a particular moment in time. Consequently, our findings do not allow us to prove causality. This is because we cannot tell if media exposure raises anxiety or whether those with anxiety gravitate toward news and therefore spend more time on social media. To properly predict the potential effects of a global epidemic, more in-depth research might follow those who exhibit high and low degrees of fear to see how social media is used and the stress levels that develop in reaction to the danger.Similarly, additional factors that explain the connections between observations are regarded as possible third variables. Unfortunately, we did not measure neuroticism in our survey, which is an interesting area for future study. Moreover, all the data were obtained via self-report surveys, and they may have been influenced by shared method variation since they rely on self-reporting. Future mixed-techniques studies, such as interviews, would diversify the measuring methods used. While the data were restricted to the sample of social media users, they were at last assembled. To validate these results, further research should be conducted in other samples, such as those working in other settings with fear who are especially susceptible to pandemic disease risks  and thosThe study concludes that social media was responsible for spreading COVID-19 fear among people in China. Meanwhile, during this health crisis of the outbreak of COVID-19, trust between citizens and the state had declined, which is why official statements, news, and information provided by the Ministry of Health and government agencies met the needs of people. Therefore, they rely heavily on social media platforms to obtain information about viruses. The nature of social media panic among people depends on gender, age, and level of education. It can be seen that social media has played a crucial role in spreading the fear of the spread of COVID-19 in China and other countries. According to media experts and academics, we believe that we and Chinese comminutes now have an essential role in the future. We must educate media users about good things, reliable information, and a way of thinking critically since younger people are also getting a lot of information through the internet and then spreading it to their family and friends. A university is an ideal place to design courses and symposiums that can help students and teachers figure out how to find, search for and evaluate health information in someone’s case during Epidemics.The scope of the investigation varies, but those affecting the research process are important. There was a lack of literature on social media about COVID-19, so this study relied on novel research available but was very limited. In addition, conducting research required data, so data collection was another hurdle due to the lockdown period. Because of the data collection, we had difficulty finding participants who wanted to respond and participate.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.All authors listed have made a substantial, direct, and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Autism spectrum disorders represent a challenge for professionals, who must include in their individualized educational interventions goals for core symptoms  and comorbidities. The narrowness of interests and the high frequency of repetitive behaviors in children with autism often constitute an obstacle for learning and the quality of life, and for their caregivers as well. In the scientific literature, behavioral interventions based on both aversive and, less commonly, positive procedures have been implemented to reduce the frequency of stereotypies. The following study was carried out with the intention of replicating a Stimulus-Stimulus Pairing procedure applied by Nuzzolo-Gomez, Leonard, Ortiz, Rivera and Greer (2002) in order to reduce stereotypies in children. This procedure was applied to three children diagnosed with autism aged five, almost six and seven years, in order to reduce stereotypies when children watched movies. An A-B-A experimental design with three subjects was used for this research. The results showed a decrease in stereotypies in favor of appropriate behaviors. Children with Autisms Spectrum Disorders (ASD) are characterized by social communication deficit and a tendency to engage in a pattern of restricted and repetitive behaviours, including sensory anomalies, feeding issues and challenging behaviours . Similarwww.scienceofbehavior.com, accessed on 13 September 2021).Respondent conditioning occurs when an organism responds to a new event based on a history of association with a biologically important stimulus. The Russian physiologist Ivan Pavlov discovered this form of conditioning at the turn of the century. He showed that dogs salivated when food was placed in their mouths. This relation between the food stimulus and salivation is called a reflex and occurs because of the animals’ biological history. When Pavlov rang a bell just before feeding the dog, it began to salivate at the sound of the bell. In this way, new features (sound of the bell) controlled the dog’s respondent behavior . Thus, presenting stimuli together in time  is the procedure for respondent conditioning. If a conditioned stimulus (CS) comes to regulate the occurrence of a conditioned response (CR), respondent conditioning occurs  has been used to condition vowel sounds in students with a limited verbal repertoire  and to ewww.aipass.org/node/11560, accessed on 14 September 2021) and Child Development  as well as the BACB’s ethics requirements . Furthermore, certified behavior analysts, as supervisors of the participants, informed their caregivers in understandable language about the nature of the research and its publication; about significant factors that could influence their willingness to participate; answered any other questions participants had about the research; and informed them that they were free to depart from the research at any time without penalty [The participants, aged 70 months on average (DS = 12.5), were selected on the basis of a diagnosis of ASD made by experienced clinicians based on the criteria of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and assessments by means of standardized diagnostic instruments: the Autism Diagnostic Observation Schedule–Generic  ADOS-G, Participant A was a seven-year-old boy with a diagnosis of ASD and mental retardation who attended the first year of primary school two weeks a month for four hours a day with a shadow teacher and school educator. The child’s diagnosis was established by an external child neuropsychiatry equip through a protocol that involved the ADOS, ADI-R and Griffith Scales. At school, this child worked separately from the class group and carried out speech therapy and neuro-psychomotricity sessions at school assigned by public health service. The child communicated mainly using single words, responded to simple instructions, recognized at least one hundred objects and named about fifty images and objects before the training. He also walked on his toes, showed motor stereotypies  that limited the learning of new skills, functional play and daily life activities. The child had been attending a behavioral treatment for two alternating weeks for a month for a total of 40 h a month. Participant B was a five-year-old boy diagnosed with ASD who attended kindergarten every morning with a shadow teacher and an ABA tutor who spent six hours with him. The child’s diagnosis was provided by an external child neuropsychiatry equip through a protocol of ADOS, ADI-R, and Psychoeducational Profile PEP-3 . The chiParticipant C was a five and a half year old child diagnosed with ASD, as established by the pediatric neuropsychiatry equip, through the administration of the ADOS, ADI-R and Griffith scales. The child was able to match images and objects. He was able to imitate movements with objects or even lines or simply drawings, recognize and discriminate objects and images, and play in turns displaying symbolic plays. He used an electronic Augmentative Alterative Communication (CAA) system, vocalizing the selected icons and adding images of new categories. This system was installed on the child’s personal tablet, and he was able to form phrases with object + adjective and to answer simple social questions. The child displayed a variety of interests and responded to social reinforcement. However, he exhibited numerous motor stereotypies that limited his ability to respond to adult’s requests in his daily life. He had been following a behavioral weekly intervention involving 6 h of treatment per week, divided into three sessions of 2 h. The therapy included one hour of one-to-one therapy and one hour of therapy in the playroom with other children.The training of participant A was conducted at the centre in a room where there was a table and a shelf with play items. The training of the participant B was conducted at the child’s home, in a small room containing a bed, a wardrobe, a shelf with visible play items and a toy box containing games and materials used during the therapy sessions. The training of the participant C was conducted at the centre in a room used for standard therapy, in which there was a table, a chair and a computer used for watching cartoons. The current program comprised an assessment of the efficacy of the training SSP based on a repeated baseline (pre and post probes with follow-up). Each weekly session of training lasted 400 seconds and was conducted with a 1:1 ratio between the tutor and participant. The participants correspondingly needed 48, 22, 9 sessions, respectively, before acquiring the mastered criterion of the training. The materials that were used for the probes and stimulus-stimulus pairing sessions included a table, a chair and a computer. During the procedure, the children were seated on the chair, and the tutor was placed behind them in order to be a moderate presence but at the same time able to deliver reinforcers. The therapists used a pen for data recording, a data sheet, and a timer to measure the stereotypies of children occurred during the training, following two categories of intervals: the SSP (respondent conditioning) and observation intervals (see Procedure for more details). The study employed an A-B-A experimental design on three single subjects with follow-up . RegardiConcerning the training, we operationally defined the behaviors that were recorded during the probes and during the intervention and coded appropriate behaviors shown by children with a plus sign  and inappropriate ones  with a minus sign A preference assessment was also conducted, and the first reinforcers identified in the hierarchy were used for the training. We selected a specific reinforcer for the training and deprived the children of that reinforcement for the rest of the time . We performed two probes of five minutes (A), each divided into 60 five-second intervals, for data recording. Each participant was asked to sit in front of the table on which a computer displayed cartoons. During the probes the experimenter did not provide any correction and did not deliver reinforcers, merely recorded the data. During the intervention phase (B), the experimenter was positioned behind the child in order to easily deliver the reinforcer and be less invasive. Each intervention session included 20 learning units, which consisted of ten seconds of pairing alternating with ten seconds comprising only behavior observation (Test Condition). During the pairing intervals, no instructions were given, motor stereotypies were blocked, and physical guidance was provided to place the hands of the children on the table, redirecting the child to the computer. After these behavioral strategies, the reinforcer was delivered. During the test intervals the experimenter only recorded data. The mastery criterion was set at 90% of correct intervals for two consecutive sessions or 100% of correct intervals for a single session. After the acquisition of the criterion, two post-probes were carried out in the same way as the pre-probes. After one month from the end of the intervention, we conducted a follow-up to evaluate the appropriate behaviors and the reduction of stereotypies. The follow-up was conducted in the same way as the probes. No other intervention on the reduction of stereotypies was introduced during the training. The dependent variables in this study were the percentage of the number of intervals in which appropriate behavior was emitted and the percentage of the number of intervals in which stereotypies occurred during the test conditions. The independent variable introduced was represented by a stimulus-stimulus pairing procedure conditioning appropriate behavior during the movie watching.During the probes, data were recorded by the experimenter using a data sheet in which the intervals were already divided in sections of five minutes. We used a pencil and paper procedure with a mobile application that provided an alert whenever an interval concluded (10 s). For each interval the data were recorded using a positive sign (+) for a correct answer and a negative sign (−) to encode inappropriate behaviors, stereotypies, and passivity. The data were plotted on a graph showing the percentages of the number of intervals during which the appropriate behavior was exhibited and the number of intervals in which inappropriate behaviors occurred. During the intervention, the experimenter collected data concerning 20 test conditions. Specifically, each learning unit included 10 s of pairing alternating with 10 s of testing in which the experimenter simply collected the data without interacting with the child. After completing 20 pairing and testing intervals, the number of intervals in both those with appropriate behavior and those with inappropriate behaviors were plotted on a percentage graph. In both probes and during the intervention, whole-interval recording (WIR) was used for appropriate behavior. That is, the behavior was coded using the positive sign (+) only if it occurred throughout the interval (10 s). Regarding the inappropriate behaviors (stereotypies and passivity), partial interval recording was used. For example, it was coded with the negative sign (−) if the behaviors described above occurred in a partial time interval within 10 s.Starting from the descriptive statistics collected on the percentages of positive intervals (appropriate behavior) and negative intervals (stereotypies) during the probe and training session, participant A in the two pre-probes showed an average of 28.3% positive intervals (DS = 2.36), and in the post-probes showed 91.67% positive intervals (DS = 2.36), showing a significant increase in functional behaviors and a decrease in stereotypies. The training mastery criterion was reached after 48 sessions. Likewise, participant B in the two pre-probes showed an average of 36.67% positive intervals (DS = 4.71), and in the post-probes showed 95% positive intervals (DS = 2.36), showing an increase in functional behavior and a decrease in stereotypies. The training mastery criterion was reached after 22 sessions. Finally, participant C in the two pre-probes showed on average 3.5% positive intervals (DS = NA), and in the post-probes showed 63.5% (DS = NA) positive intervals. The training mastery criterion was reached after nine sessions of training. After 30 days from the end of intervention, a follow-up was conducted. Participant A displayed 86.6% positive intervals, participant B 83.3% positive intervals, and participant C 100% positive intervals (please see the The current study aimed to gather information concerning the efficacy of respondent conditioning (stimulus-stimulus pairing) on the stereotypies of three children with autism. Likewise, we have replicated the researches of Nuzzolo-Gomez, where edible and social reinforcers were delivered while children observed books and played with toys. Specifically, the reinforcing stimuli and neutral stimuli (such as books and toys) were associated during free play sessions. Hence, in the case that the neutral stimulus became a conditioned reinforcement, it was consequently selected more often by the participant, determining the reduction of the stereotypies. In this study the stimulus-stimulus pairing procedure was not adopted to condition neutral stimuli, as in previous researches, but rather to reduce the dysfunctional use of a stimulus that was already a conditioned reinforcer, such as movies. Therefore, the data obtained by training show the efficacy of SSP along with response blocking in reducing the stereotypies of the children enrolled. In fact, only a few training sessions were generally needed to determine an increase in appropriate behaviors and a decrease in motor stereotypies. Going by the number of sessions needed by the participants in order to acquire the mastery criterion of training, we also ought to consider the clinical differences of the children at their respective baselines, which can have an influence on the results, as well as the previous behavioral interventions they have been following . For example, participant A reported a double diagnosis of ASD and mental retardation, with 48 sessions to reach the mastery criterion. As a result, the severity of symptoms could have an impact when using outcomes as guidelines in behavioral intervention reports. Nevertheless, the current procedure is based on manualized reinforcement schedules, referring to respondent and operant conditioning. Consequently, the paper shows that these behavioral applications are corrected on the basis of efficacy and evidence . FurtherConcerning the duration of intervals  where appropriate behaviors occurred, we can hypothesize that the data that emerged during the application of the procedure are the result of a generalization process, without prior learning for those specific conditions. Generally, in typical development the generalization is inherent in the learning itself where it occurs naturally. It is possible to explain the generalization as a learned behavior in response to different antecedents from the original with shared characteristics. Thanks to generalization, a person’s ability to act in new situations similar to others becomes natural. Likewise, the participants in this study, in fact, met the criteria for mastering the procedure in adequate time. Increasing appropriate behaviors in place of stereotypies while watching the videos has allowed these children’s parents to be able to manage their free time in a more functional and adequate way, helping to improve daily family organization, especially at home. However, the present study shows some limitations. First, the absence of agreement between observers (IOA); the work organization of the center provided a 1:1 ratio between the therapist and the child and clinical staff. Additionally, at the time of training, the treatment center was not able to provide any other employees. Another limitation is given by the fact that while follow-up was conducted for the three participants, generalization of their learning in other settings was not verified in the absence of adults or in the presence of people other than the therapist. This limitation of the conditions of generalization across contexts and people should be better assessed in future studies through cross-sectional follow-ups, in order to evaluate the effectiveness of the stimulus-stimulus pairing independent of the context in which it is implemented and of the people who implement the procedure, which would be able to demonstrate clinical as well as procedural efficacy. On the other hand, in order to ameliorate the research methodology of the single case studies, it is possible to apply a multiple baseline design across participants, controlling and manipulating the independent variable. Moreover, concerning the research design used, the removal of the independent variable after the intervention phase does not determine the return to the starting condition; this constitutes a procedural limit. However, it can be considered a clinically desirable result. It was not possible to demonstrate the existence of a functional relationship between the dependent variable and the independent variable; however, in the removal phase of the intervention, the participants showed a high percentage of ranges of appropriate behaviors. Future developments of this research could provide a return to the baseline after the teaching phase, formalizing an unpairing process in order to evaluate both the effectiveness of the functional relationship in the intervention phase and the number of sessions necessary to implement an unpairing process when compared with the number of sessions required to implement it. Some ethical limitations, however, should be considered in this case, above all due to the risk of a failure to re-condition the stimulus itself. Having more stimuli could be helpful in bypassing this problem.Finally, despite the limitations described above and the usefulness of extending the research, this work confirms the results reported in the literature, namely that it is possible and preferable to select positive procedures for the reduction of problematic behaviors in order to obtain equally effective results. Essentially, applications based on SSP can help professionals to address the restricted interests and stereotypies of children with autism in order to expand their tailored educational programs and settings. These opportunities could serve to reduce core symptoms, with the purpose of allowing more reinforcements and collaboration in learning in both discrete trial teaching and in natural conditions.Currently, children with autism spectrum disorders represent a professional challenge since they show deficiencies in social communication and stereotypies/restricted interests and comorbidities . Behavioral interventions applied in either early childhood or in adolescence has demonstrated efficacy in increasing skills and in reducing the types of challenging behaviors which limit learning. Clinicians and behavioral analysts can refer to manualized and research-based treatments before the implementation of an individualized behavioral program, either comprehensive or focused on people with autism. The following study, starting from the main principles of behavioral science , was carried out with the intention of replicating a Stimulus–Stimulus Pairing procedure to reduce stereotypies in three children with autism. The current results show a decrease in stereotypies in favor of appropriate behaviors during movie watching. Likewise, we have discussed the ways that these conditioning procedures can have an impact in other educational programs involving a variety of interests in order to ameliorate functional play using more reinforcements for both structured and natural teaching. Finally, since the narrowness of interests and the high frequency of repetitive behaviors in children with autism often constitute an obstacle for learning, reducing the quality of life of their caregivers, these behavioral programs respond to a major social need, ameliorating learning opportunities and family routines.


Recent election surprises, regime changes, and political shocks indicate that political agendas have become more fast-moving and volatile. The ability to measure the complex dynamics of agenda change and capture the nature and extent of volatility in political systems is therefore more crucial than ever before. This study proposes a definition and operationalization of volatility that combines insights from political science, communications, information theory, and computational techniques. The proposed measures of fractionalization and agenda change encompass the shifting salience of issues in the agenda as a whole and allow the study of agendas across different domains. We evaluate these metrics and compare them to other measures such as issue-level survival rates and the Pedersen Index, which uses public-opinion poll data to measure public agendas, as well as traditional media content to measure media agendas in the UK and Germany. We show how these measures complement existing approaches and could be employed in future agenda-setting research. The political agenda is the set of issues that are the subject of decision-making and debate within a given political system at any one time . It is aThe most developed way to assess agenda change and to capture these complex dynamics is through the measurement of volatility, that is, a measure of the tendency of a system to change rapidly and unpredictably. There are multiple ways of defining and measuring volatility across and within disciplines, including the natural sciences and social sciences. In this paper, we first discuss differences between alternative definitions of volatility. Second, we propose a definition of volatility in agenda setting that comports with concepts of volatility used in political science as well as those used in political communication research and information theory, and operationalizes this definition by developing measures of agenda fractionalization and agenda churn that can capture the dynamics of the agenda-setting system as a whole. The measures discussed here can be used widely across the study of political systems, for example, to assess the extent to which volatility is increasing empirically in multiple spheres, effectively allowing for public opinion (the public agenda) to be compared against media salience (the media agenda), electoral politics, and legislative attention. We argue that these measures complement existing approaches to capture the overall effects of the complex dynamics of gradual and rapid agenda change over time. Third, the metrics proposed here are compared to other measures of volatility using four empirical case studies, taking data over the last 70 years from public opinion polls and traditional media in the UK and Germany. Finally, we discuss how the measures of volatility in political attention proposed here, combined with measures of volatility in other domains, could be employed in future research in agenda setting.In political science, a core notion of volatility is found in the Pedersen Index, which measures the net change within an electoral party system resulting from individual vote transfers between parties from any one election to another . The PedPolitical communication studies of voter volatility have also studied volatile behavioral variables, such as unstable party affiliation, openness to alternatives, anti-party attitude, and vote abstention, all of which aim at measuring how a voter might behave in a volatile manner . In spitIn the policy agendas literature, scholars have studied the frequency and magnitude of individual fluctuations or events on the agenda. In general, the distributions of issue agenda fluctuations are leptokurtic and heavy-tailed. They are leptokurtic as most changes in the importance of an issue are very small, leading to a concentration around the mean. On the other hand, rare events called “policy punctuations”—sudden but rare breaks in an agenda series —lead to In  communication research, the agenda has been assessed in terms of three concepts: capacity (the number of issues on the agenda at any one time), diversity or fractionalization , and issue volatility , following the seminal work of This study builds on the work cited to conceptualize agenda volatility as a system-level phenomenon, encompassing both the fractionalization or diversity of the agenda and its change. As a result, it proposes two composite measures that conceptualize volatility more widely than proposed by This study proposes two quantitative measures of political volatility drawing from information theory. The first measures fractionalization or the number of issues receiving attention simultaneously, while the second measures the change in the agenda between two points in time.tENI, defined in X of n issues. Below, tp(ix) indicates the attention received by issue ix at time t, and tH(X) stands for Shannon entropy ENItn, the total number of issues on an agenda or the total number of species in a system. Its interpretation is also the same as for Laakso and Taagepera’s effective number of political parties, which similarly draws from ecological diversity indices to measure the number of parties and their relative sizes in the electorate  or in the legislature  to calculate the number of “hypothetical equal-size parties that would have the same total effect on fractionalization of the system as have the actual parties of unequal size”  is divided between multiple simultaneous issues, weighing issues according to how much attention they receive to calculate what number of evenly considered issues would produce the same level of fractionalization. This measure is highest when attention is evenly distributed across many issues and lowest when it is concentrated on a single issue.tH(X) in Laakso and Taagepera compare e agenda , and hase agenda . Other we agenda , and havENI, unlike Shannon entropy, can be directly compared to real numbers of issues in an agenda. In other words, it can be interpreted as the degree of fractionalization of an agenda, ranging from 1, when all or nearly all attention is given to a single issue, to n, where public attention is distributed uniformly across n issues. One would expect the latter scenario to be unlikely, given the limits on our capacity for processing information—the famous “magical number” of seven plus or minus two, which suggests one might expect five to nine issues to receive most of the attention at any single point in time  directly.The average issue survival rate, presented in More generally, single-issue measures only provide a partial picture of agenda stability. While Baumgartner and Jones’s original focus is on identifying agenda punctuations, there are usually long periods between punctuations, in which an agenda might show varying levels of stability. To understand these periods, whole-agenda measures are necessary.tp, which designates an agenda at time t. For example, for an agenda composed of 20 issues, if one issue went down 20 percent while other two issues went up by 10 percent each, the resulting Pedersen Index would be of 20 percent ((20 + 10 + 10)/2 = 20).A simple system-level approach would be to apply measures of voter churn based on the Pedersen Index, defined as the total net change within an electoral party system resulting from individual vote transfers, divided by 2 , as showThe Pedersen Index has been used in multiple contexts over the last decade . SimilarDespite their common usage, the simplicity of Pedersen-like indices is also their limitation. For instance, for the agenda described above, if instead all 20 issues were to change 2 percent in importance from one month to another, they would yield the same Pedersen Index of 20 percent (since (2 × 20)/2 = 20). This simple observation suggests that Pedersen-like indices might not be an appropriate measure of unpredictability or surprise, since small fluctuations in the importance of many issues might produce the same Pedersen Index as a single large fluctuation. Given how common such small fluctuations in issue importance are (producing the leptokurtic distribution discussed earlier), this is likely a meaningful limitation. In contrast, a useful measure of volatility in political attention should reflect the fact that large, sudden changes in the political agenda are less likely than many small fluctuations.Even though measurement systems have developed in robustly capturing changes in the allocation of attention and in government activity , still ntp and same distribution at a previous time t−p1 as a whole-agenda measure of agenda change. It is possible to speak of the KL divergence of an agenda at different time intervals . The KL divergence between tp and t−p1 is presented in We propose the KL divergence between the distribution of attention over issues at a given point in time 2(tp(ix)t−/p1(ix)) term. Because of this weighting, relatively small fluctuations in an agenda result in a small KL divergence, whereas large fluctuations result in a large KL divergence.Unlike the Pedersen Index, KL divergence weighs changes by their relative magnitude, as indicated by the logp and q are two probability distributions, KLD(p|q) is a measure of how much information is gained from p assuming that q is known. If they are the same, information gain is zero. It is important to differentiate the KL divergence from the Jensen–Shannon divergence, a symmetric measure derived from the KL divergence that has also seen application in the social sciences , while an increase in KLD indicates more instability, that is, a rise in volatility.Apart from its many uses in physics and machine learning, the KL divergence has also been used to measure cognitive surprise , changesThe measures presented here were tested in four case studies, representing the combinations of two types of agendas, namely public opinion polls and news articles, with two countries, namely Germany and the UK. The reason for choosing such sources of agendas is that both environments show little friction and so may be subject to volatility and that both can be measured over a long period of time. As for the countries, the UK and Germany meet two different kinds of selection criteria. First, they represent different forms of democracy. The UK political system, which is centralized and lacks veto players, has been associated with receptivity to policy innovations and also liability to policy disasters , though Naturally, such a short list of data sources might raise questions about the applicability of these measures to new datasets. We note that the datasets considered here are not an exhaustive list of where the measures can be applied. Rather, they are simply the minimum necessary to illustrate the versatility of the measures discussed in this study: two public opinion polls collected in different countries over different time periods, and two news vehicles publishing in different languages. The formulas for the effective number of issues and the KL divergence require only a distribution of attention over multiple issues over time, and can therefore be applied easily to any dataset of this type.The public opinion poll datasets analyzed here are taken from attitudinal surveys that ask nationally representative samples of the British and German populations what they feel is the most important issue facing their countries on the day.For the UK, the surveys used here are summarized as the Ipsos MORI long-term Most Important Issues Index, which corresponds to monthly surveys, each of a representative sample of approximately a thousand British adults, asking the open-ended question “What do you see as the most important issue facing Britain today?” and coding responses into different issue categories. The dataset considered here includes all monthly rounds of the Ipsos MORI survey since 1985 (earlier years were discarded due to most issues not being encoded in the first years of the survey).The analogous dataset used here for Germany is the German Longitudinal Election Study (GLES), collected every three months. Although GLES is an electoral study, this investigation only considers its long-term cross-sectional surveys, which have been carried out at regular intervals since 2009, with stratified samples of German residents according to age, gender, and education. This study uses hand-coded responses to the free-response question “What is, in your opinion, currently the most important political problem in Germany? Please only state the most important problem,” taken from 2010 onward. This long-term tracking produces data in a format comparable to the Ipsos MORI long-term Most Important Issues Index.A heatmap showing UK public attention to different issues by month from 1985 to 2016 is shown in Migration and Integration issue becoming the dominant issue at the time.To examine shifts in public attention, the distribution of attention to issues over time was computed. Defense/Terrorism issue  , which aThe reason LDA topic modeling is particularly suited for this task is that the distribution of topics can be considered analogous to a distribution of attention to different issues. This analogy makes it straightforward to measure the effective number of issues and the KL divergence between different editions of the same newspaper or magazine. This can be done not by comparing the absolute values for these measures, as they are influenced by the number of topics chosen, but rather by comparing these measures across different data sources.The Times and the Germany-based weekly news magazine Der Spiegel. To allow for a better comparison between both sources, the dataset studied here considers one day a week of content from The Times , starting from 1947, the year when Der Spiegel was founded. All articles for Der Spiegel from 1947 to 2016 were obtained directly from the news magazine’s website.The Times was obtained from The Times Digital Archive, which contains digitized editions of the newspaper from 1785 to 2012 ( to 2012 . The TimExamining the contents of the entire paper, rather than just the first or first few pages, is a direct consequence of the focus of this study: rather than studying only the most important issues in the newspaper, we track the distribution of attention across all issues discussed by the newspaper. This echoes the desire to measure the system-level change in the agenda over time, rather than only looking at punctuations or at its most important issues.The Times, and a sharp decline in the first half of the 2010s in Der Spiegel.Both news publications show wide variation in the effective number of issues per week see , showingThe Times and Der Spiegel show different behavior from each other. As shown in The Times is approximately constant from 1947 to 2012, suggesting that its monthly churn of attention to different issues is relatively constant over time. For Der Spiegel, at the bottom of Der Spiegel also increases in early 2010, simultaneously to the sudden decrease in the effective number of issues shown in Der Spiegel and The Times.As discussed above, the effective number of issues measures the fractionalization of issues present in an agenda. Under the lens of KL divergence, The Times (The news media data also provide a good illustration of the difference between the KL divergence and other measures. The difference between the KL divergence and averaged issue survival rates is particularly evident when large shifts in the agenda do not consist in the decay of any particular issue, but rather in the sudden rise of a group of issues. This is true for all major punctuations in he Times , which cThis paper conceptualizes the idea of volatility as it applies to the whole of the political agenda, bringing together concepts, models, and frameworks from political science, communication research, information theory, and computational techniques, to complement existing measures of political attention across media sources and public opinion. Following a review of measures of volatility in other domains, we operationalize the concept with two measures. The first, the effective number of issues, measures the fractionalization of the agenda, or how many issues are being considered simultaneously, and the second, the KL divergence or novelty, measures how quickly attention shifts from one set of issues to another over time. These measures complement existing scholarship in two key ways. First, the effective number of issues provides a measure of agenda fractionalization that allows for the same intuitive interpretation as Laakso and Taagepera’s effective number of parties and allows for comparisons across agendas with different numbers of issues. This stands in contrast to the normalized measure of diversity provided by Both measures are then used to assess the volatility of public opinion polls and news media data in the United Kingdom and Germany. Topic modeling is used to translate news articles into distributions of attention to different issues, thus making it possible to measure the effective number of issues active in the news media, and also to calculate the month-to-month change in the news media agenda as a whole.Not only does the effective number of issues in each dataset vary over time, but the estimate that the public would consider of 5 to 9 issues at a time  is also The results here show that peaks in the KL divergence correspond to policy punctuations, that is, large shifts in attention . These gDer Spiegel and The Times changed formats multiple times within this time range, alternating between broadsheet and tabloid formats, launching online and regional editions, and being affected by political changes such as the reunification of Germany in 1990. Naturally, any changes in the effective number of issues due to factors such as these cannot be determined from volatility measures alone. One confound that can be ruled out, however, is a change in the number of articles per month: as shown in Der Spiegel was covering even fewer issues than expected when taking into account the number of articles during the period.For the news media, it is worth noting that both newspapers went through many changes from 1947 to 2016, many affecting content and length of publications. Both It is also important to note that the data presented in this paper do not capture recent historical developments involving UK and Germany, such as the political crisis in the UK following the 2016 EU membership referendum which, along with earlier events such as the demonstrations after the Arab Spring from 2011, have suggested an increase in system instability or volatility , causingOverall, the development of new ways to measure volatility in political attention opens exciting avenues for political science and agenda-setting research, outlining a future research program that can ascertain the extent and variation in volatility in political attention and investigate possible underlying causes in comparative contexts. The more rigorous operationalization of the concept of volatility in agenda setting presented here, done through information theory and the KL divergence, also raises further questions regarding the connection between novelty, changes in public concern, legislative action, and democratic outcomes. The measures that we have operationalized can be applied to both media attention and public opinion, as done here, but future research might apply the same measures to other domains within political systems, such as public expenditure and legislative attention, in terms of how much parliamentary time is spent on different issues. With an information-centric and multidisciplinary approach, our measures of volatility in political attention will enable further research in this important area.https://github.com/euagendas/POLVOL.REPLICATION DATA AND DOCUMENTATION are available at: https://doi.org/10.1093/poq/nfab032.nfab032_Supplementary_DataClick here for additional data file.