Seventeenth-century UK experienced an epidemic of the newly recognised disease rickets, its nutritional and environmental causes then unknown. This is evident from parish burial registers, the London Bills of Mortality, and contemporary medical descriptions and treatments. Rickets appeared to be killing 2–8 per cent of urbanites, especially wealthy children.Rickets emerged as a threat to child health in early modern UK as a result of coal dependency and climate, and social differences in infant and child feeding. Physicians investigating rickets showed concern for rich children’s diets. Lack of breastfeeding promoted calcium deficiency among wealthy infants, while poorer children’s meagre childhood diet retarded recovery.The seasonality and age incidence of rickets deaths corroborate this diagnosis, but after 1700 rickets deaths dwindled even as medical treatises and osteological evidence suggest rickets morbidity increased. Chronology and share of mortality of other causes relating to rickets morbidity are considered: scurvy, hydrocephalus and whooping cough. Diagnosis from cause of death descriptors is a central problem of historical investigations of mortality, especially those covering a period of several centuries.Statistical investigations of recorded causes of death provide clues gleaned from seasonality and age incidence. Direct evidence of disease may be gained from archaeological investigation of human remains. Treatises and other publications by medical practitioners provide invaluable contemporary testimonies of patients’ symptoms, although medical practitioners were not involved in compiling seventeenth- and eighteenth-century mortality records, and most showed little interest in them.In seventeenth-century UK, the environmental and nutritional deficiency disease rickets emerged as an apparently new disease of childhood. To contemporaries, it was fascinating because of this newness, and alarming because of its rapid rise in incidence, its apparently disproportionately mortal effect on children from wealthy households, and the deformities and debility that it caused. The aim of this article is twofold. Firstly, to demonstrate the value of pursuing plural lines of enquiry to diagnose historical causes of death, through the exemplar of rickets. Secondly, to use this exploration of a deficiency disease to probe environmental circumstances and nutritional status of seventeenth- and eighteenth-century urbanites, especially children, at a time when overall English child mortality rates were severe, and worsening most markedly of all in London.Rickets is perhaps best known historically as a disease of childhood in the urban slum, but it is still seen today, even in affluent countries, among children who have received restricted exposure to sunlight, an inadequate diet, or both, and are therefore deficient in Vitamin D and/or calcium. Rickets has been known in medicine as the ‘English disease’ since its first description by Whistler in 1645 and is still referred to as such.Vitamin D is a key part of calcium metabolism, which when disrupted impairs bone mineralisation and growth in children, leading to the well-known and visually distinctive skeletal deformities of rickets, affecting especially the long bones, ribs, skull and pelvis. Pregnant women, their foetuses and young children are particularly susceptible because of the high mineral requirements of growing bone. In older children, difficulties in standing and walking are typical. In infants, acute hypocalcaemia can be fatal. However, if calcium intake is high, and bioavailability good because the food contains soluble calcium salts that are well-suited to human digestion (as with breast-milk), passive absorption of calcium without Vitamin D can occur.Natural dietary sources of Vitamin D being few and meagre, the primacy of sunlight in providing Vitamin D has drawn some scholarly attention to the relationship between rickets and environmental conditions in England during industrialisation. For example, Hollick notes that in 1822, the Polish physician Sniadecki referred to rickets as ‘the English disease’ when making his ground-breaking observation that sufficient exposure to sunlight could cure urban children of rickets.Fumifugium, which also compares London unfavourably to elsewhere: ‘For when in all other places the Aer is most Serene and Pure, it is here Ecclipsed with such a Cloud of Sulphure, as the Sun it self, which gives day to all the World besides, is hardly able to penetrate and impart it here.’ Blockades on coal leaving Newcastle during the Civil War years provided a natural experiment that seemed to prove coal was the culprit.Increasing fogs and gloom from coal smoke in Victorian and Edwardian London are well-documented.Rising coal imports to London in the sixteenth century attest to the fast-growing adoption of coal as a fuel.Importantly for the geographical specificity of rickets, and perhaps other so-called ‘English’ diseases, this degree of dependence on coal as a fuel at such an early date was a peculiarly English phenomenon. Elsewhere in Europe there were densely populated cities consuming large amounts of fuel, particularly in the Low Countries, but the fuel there was predominantly peat, and only selectively in certain industries were smoky ‘sea-coals’ used.Intensification of the built environment in poorer London suburbs over the seventeenth century probably exacerbated reduced exposure to sunlight from smog.The seventeenth-century rickets epidemic is observable through annual rickets deaths in the seventeenth-century London Bills of Mortality, compiled from the reports of clerks who also kept the burial register in each parish. Individual rickets burials can also be observed at source, among causes of deaths that were recorded in the burial registers of some parishes.The number of rickets deaths in London increased rapidly after its first appearance in the Annual Bill of Mortality for 1634, when 14 died of rickets. Scattered weekly Bills of Mortality attest to the presence of rickets in every year of incomplete annual data between 1635 and 1647, ending with 142 rickets deaths in the near-complete 48 week series of 1647. By the 1650s 300–400 rickets deaths were usual in each year. Rickets sustained a similar number of deaths following the population changes and temporary disruption to record-keeping of the Great Plague of 1665 and Great Fire of 1666. As shown in The rise and fall in rickets as a cause of death raises several questions. Firstly, why did rickets emerge as a cause of death in the seventeenth century? Secondly, why did its death toll apparently dwindle to zero in the eighteenth century although, as we shall see, there is every indication that the disease remained prevalent? And thirdly, did rickets actually cause the deaths of those ascribed to the disease?x-axis for reference. Deaths are shown relative to an index of 100, which would indicate an equal share of burials in each division of the year. Teeth (teething) is a major cause of death applicable to children in roughly the same young age group as rickets deaths are likely to fall, so the index values for teeth burials in the same decade are also plotted for comparison.An examination of rickets seasonality from the weekly Bills of Mortality is useful to establish at the outset whether rickets had any cohesive identity. Only partial years survive before 1665, and the second half of the 1660s are disrupted by plague, fire and subsequent reconstruction. Therefore the 3,983 rickets burials from the following decade 1670–9 were analysed. Their seasonality in thirteen divisions of the year is shown in The seasonality of rickets and teeth deaths are strikingly distinct from each other, with rickets deaths peaking in late winter and spring, in contrast to the strong summer peak of teeth burials . The seasonality of rickets deaths is certainly not random, and accords with the seasonal incidence of Vitamin D deficiency expected today at high latitudes, where the late spring months of April and May follow many months of total deprivation and Vitamin D deficiency is at its most acute. The timing of the initial rise in the rickets seasonal index in period 12 (October–November) is coincident with the beginning of the period when Vitamin D cannot be synthesised.Other essential micronutrients such as Vitamin C, found in fresh produce, would also have been less available in the winter months outside the growing season, and it is possible that some of the seventeenth-century rickets sufferers also had other deficiency diseases, such as scurvy. The chronology of scurvy as a cause of death descriptor in the Bills of Mortality, also shown in The pattern of few summer and early autumn rickets deaths compared to the spring and winter death toll that is apparent for London as a whole is also discernible in some of its constituent parishes that recorded causes of death, providing an important check on the consistency of identification of disease and also allowing some examination of earlier rickets deaths from the 1650s. The seasonality of rickets burials in the populous northwestern suburb of St Giles Cripplegate in the 1650s is tipped towards the spring and winter months, with fewer deaths in summer and autumn. In three complete years 1654–56 covered by the burial register, 39 rickets burials fell between December and May and only 15 between June and November. In the small central city parish of St Michael Cornhill also in the early 1650s, during four complete years 1653–57, 8 of 11 rickets burials occurred between December and May.Parish registers are particularly valuable for the individual-level glimpses of what sorts of Londoners rickets affected they permit. Among causes of death ascribed to children, there is also local variation in the proportion said to die of rickets. Most usefully of all, parish register sampling permits scrutiny of age incidence of rickets in different parts of the metropolis. The Bills of Mortality tell us nothing about the ages of those suffering from rickets, as age breakdowns were not included until 1728, and then not on a cause-by-cause basis.The highest rate of rickets burials in parish registers was discovered in the small parish of St Michael Cornhill in the city centre, where rickets represents the joint second ranking cause of death, together with consumption, with only convulsions claiming more lives. Few parish registers record cause of death at this time, but the importance of the St Michael Cornhill rickets evidence must be tempered with cautious interpretation, since it is a small parish and any newly emergent disease might be identified idiosyncratically by some parish officers. Nonetheless, the existence of seasonal and, as we shall see, age patterns in these and other parish data are suggestive. In combination with contemporary medical treatises and osteological evidence discussed below, they bolster the case for social status-related differences in rickets prevalence.The 11 rickets deaths occurring in St Michael Cornhill occurred during a 4 year period when causes of death are almost universally recorded .The occupations of adult men dying in the parish give some indication of the social range to be found in St Michael Cornhill. Among 34 men buried in these four years, one in five was an upholder (the London guild of upholsterers). High status occupations such as gentlemen, doctor, linen draper and merchant were well-represented, but lower status occupations such as weaver and porter were also present. Further evidence on status can be gained from the 1662 Hearth Tax for Cornhill Ward. Five of the fathers of rickets casualties appear as householders in this assessment. In the entire ward, the median number of hearths assessed was 4. Two of the fathers who appear as householders were assessed for above average dwellings of 9 and 13 hearths, the latter’s high social standing indicated by the title of esquire. One father was assessed for 4 hearths, the median; and two fathers for slightly below average dwellings of 3 hearths.In the more populous suburbs, in St Martin-in-the-Fields, the Sextons Burial Books extant for 1685–87 and 1694–1703 record rickets as the cause of death for 331 persons among 8,718 child burials, or 15,856 burials in total.The Cripplegate registers do not state the age of the deceased, so ages at death were again calculated by linking burial records to baptism records. Record linkage in this parish is more challenging because of the much larger number of records, with 4,000 burials registered in the same 4-year period as the 143 registered in St Michael Cornhill. This gives rise to ambiguities from common names. A sub-sample of 25 of the 75 rickets burials in these four years from the 1650s could be assigned precise ages through an unambiguous match with a baptism record.Since these are a minority of total rickets fatalities in Cripplegate, the question of representativeness arises. However, if there is bias in the ages, it should be in a direction that suppresses the true extent of the difference with the Cornhill ages at burial, since successful record linkage is likely to over-represent the children who died at the youngest ages before their parents could move elsewhere. In consequence, the true average age of all rickets burials in Cripplegate was probably somewhat older than the linked sample suggests. The children of the only two high status fathers in the Cripplegate sample, a gentleman and a lawyer, both died very young at under 1 year of age. Fathers who were a printer and stationer, and a soapmaker might have had some stock or equipment of value, depending on the size of their businesses. Other than these, fathers’ occupations fell in Brodsky Eliot’s fourth and lowest status group of seventeenth-century London occupations. The incidence of rickets mortality in some city centre parishes more closely resembled the lower rate prevailing in the suburbs. In St Helen Bishopsgate, of 186 burials between September 1653 and April 1659 only four were rickets deaths, about 2 per cent of the total. Three of them had high status fathers: a gentleman, a perfumer, a merchant; the fourth was the child of a locksmith, a skilled trade.In the poor but populous suburban parish of St John Wapping in the East End, rickets as a cause of death descriptor seems to have passed in and out of use, suggesting that while rickets was known in this part of the city, not all Searchers regarded it as a legitimate cause of death. Extant cause of death recording begins in Wapping in June 1665, where one rickets burial is listed within the first 10 entries.In mid-eighteenth-century Whitechapel, another East End parish adjacent to Wapping, there was a similarly large proportion of pauper burials. 20 of 38 rickets burials recorded between 1743 and 1768 were marked poor. Here the stated ages of virtually all children (>99 per cent) are given, so it is possible to check whether poor or non-poor status has any effect on the age at burial of rickets fatalities. The median age among both pauper and non-pauper rickets burials was 2 years, the oldest was 5 years, and none were under 1 year. The lack of known ages for paupers among the Wapping burials thus should not distort the evidence, and the Wapping sample may be taken as typical with regard to age.t-test conducted to compare the two samples confirmed that the difference between them is statistically significant, at the 1% level .In Taking the ages of rickets deaths as an indicator of the ages at which a child could be visibly suffering from the disease, Country nursing of children potentially affects the observable ages at which urban children of different social statuses die. However, the proportion of London’s mercantile elite sending their children away to nurse was already declining by the first half of the seventeenth century, while the high status children here observed dying of rickets in their home parishes are spread throughout the first two years of life, the age group found most likely to be absent and probably away at nurse in 1695.Wealth differentials in the propensity of children to suffer from rickets at different ages are also evident from archaeological excavations. Both active and healed instances of rickets have been identified in English skeletal remains from the early modern period, and the largest studies come from London burial grounds.The osteological evidence supports the hypothesis that rich children suffered from rickets earlier in life and recovered sooner and more swiftly than poor children, and that the pattern persisted into the eighteenth century. However, in the less well preserved Broadgate specimens, identification of rickets relied heavily on the presence of bowing of the leg bones, which may over-represent older ages since although present in active cases, it is most obvious in children (and adults) with healed rickets where growth has continued.The osteological evidence is particularly important because it provides almost the only quantifiable estimate of rickets prevalence in the eighteenth century, thus further proving the near-total disappearance of the disease after 1750 implied by the Bills of Mortality is implausible. Still, there may have been some amelioration in rickets prevalence among wealthy children in the eighteenth century, for the relative frequency of rickets among burials of poor young children was somewhat higher for the earlier pre-1720 period of Broadgate burials than among the eighteenth and nineteenth century rich children of Spitalfields, at 20 per cent of child burials aged under 7 years compared to 14.7 per cent in Spitalfields. None of the rickets evidence from Spitalfields is pre-1750, but if it did include earlier burials the situation might well be reversed, given the relative social status of the two groups, and the higher apparent prevalence of rickets among wealthy children in the seventeenth century. These substantial rates of rickets prevalence are well on the way to those observed in the 1850s and 1860s among hundreds of children admitted to London and Manchester clinics, which ranged from 20 per cent to 30.3 per cent.The disappearance of rickets as a cause of death raises the question of whether rickets ever did cause the deaths attributed to it, and to what alternative cause or causes eighteenth century children dying with the symptoms of rickets might have been assigned. Some of the rickets mortality may genuinely document acute, lethal cases of hypocalcaemia, but it seems likely that many of those said to die of rickets actually died of other causes, including infantile scurvy.Importantly for the impact of rickets on child mortality in general, the combination of weakened thoracic muscles and soft rib bones it induces makes children with rickets more susceptible to respiratory illness, because the skeletal support to the lungs provided by the ribcage is impaired, as the Philadelphia clinician Parry later concluded from both observation and autopsy, remarking that ‘all know how these [rickety] children suffer from pulmonary symptoms’.Hardy has conjectured that there was an association between nineteenth century rickets morbidity and mortality from a respiratory disease that had by then become a major cause of death in young children: whooping cough.Besides whooping cough, there are two further causes of death which may be partially indicative of rickets morbidity, since deformations of the head was the most widely recognised symptom. These are horseshoe head and head-mould-shot, used interchangeably with an intermediate form of ‘horse shoe mould’ as evidenced by the eighteenth-century parish registers of Whitechapel. In Whitechapel’s burial register these descriptors exclusively represent infant burials. They are used for 63 infants dying in the years 1744–1747 whose age is between 1 day and 10 months, 10 of whom are less than one month old.Glisson and Whistler referred to the deformities of the head in children with rickets under the general term hydrocephalus, also translated by Armin as ‘Dropsie in the Head’, and hydrocephalus as a term persisted in the medical literature and eventually crossed over to become a cause of death descriptor.In the late nineteenth century, clinically observed ‘rickets hydrocephalus’ could describe swellings of the head associated with rickets, and a new wave of autopsies revealed the brains of severely rachitic children to be large and ‘watery soft’.On 27 January 1657/8, the diarist John Evelyn sorrowfully recorded the death of a much-beloved 5-year-old son at his house in Deptford near London. The intertwining of medical and lay involvement in sickness and death in a wealthy household is readily apparent. It was not customary for physicians to attend deathbeds, and children’s ailments were not their priority. Evelyn and his parents were attended by up to three physicians at a time for their own illnesses, but for his son’s illness we hear only of ‘the women and maids that attended him’, and no medical presence or treatment is mentioned, although after the child’s death Evelyn allowed a post-mortem to be performed, presumably by a physician.Rickets was initially noticed and reported by women. The first known manuscript rickets reference may have appeared as early as 1632, in a lady’s collection of home remedies.The Searchers of the Dead had the opportunity to acquire broad and frequent experience of disease and death. Older women were the natural choice for the role because it was women who nursed the sick and laid out the dead for burial.Inclusion of rickets in the Bills of Mortality brought rickets to the attention of the literate, but knowledge of the name of a disease was not necessarily accompanied by awareness or consensus on what it meant. A sense of evolving medical perceptions of rickets can be gained from early printed books. Using published sermons and plays, it is also possible to gain a sense of what was popularly understood by the disease in the oral culture that the Searchers were part of, but space constraints mean this will not be fully addressed here.Folk medicine practitioners of both sexes responded early to demand for a cure for rickets. A 1637 diatribe against quackery in London by Thomas Brian, MP excoriates ‘Donnington in Moore-fields, who […] burnes children behind the eares for the Rickets’.Theatrum Botanicum of 1640. He mentions rickets just once, following a repetition of Galenic theories on unlocking muscles or joints that have become immobile following spasms or convulsions.Leading apothecaries were quick to publish rickets treatments and descriptions of its symptoms. The first apothecary to refer to rickets in print was John Parkinson, the King’s Herbalist, in his London Dispensatory of 1649. This work is an embellished translation from the Latin of the College of Physician’s standard reference, the Pharmacopeia Londinensis of 1619. The original does not mention rickets, but Culpeper’s version contains some 20 references to medicines that might alleviate the disease, giving an indication of growing demand for rickets cures. Among these is an acknowledgement that the name and identity of the disease comes from women’s knowledge of childhood maladies, for Culpeper refers to: ‘that disease in children which women call the Rickets’.A more controversial apothecary, the College of Physicians’ adversary Nicholas Culpeper, provided a wide range of medicines suitable to relieve rickets in his None of the early rickets remedies known to us could have cured Vitamin D deficiency. The best prospect recent scholars have identified are crows’ livers, an admittedly unlikely source of Vitamin D.By the mid-1640s, medical treatises on rickets began to emerge. In 1645, 1649 and 1650 physicians published the first comprehensive descriptions of rickets symptoms, the earliest by Daniel Whistler, born in Walthamstow near London and an Oxford medical student who completed his education at Leiden; the second a chapter within an untranslated book by Arnold Boate, a Dutch physician also trained at Leiden who practised in London and Dublin ; and the last the best-known, by Cambridge-trained physician Francis Glisson, whose treatise was the result of a London College of Physicians enquiry on the subject.Rickets was not absent from medical notice in the eighteenth century, even as it disappeared from the London Bills of Mortality as a cause of death. More than forty theses entitled ‘De Rachitide’ were presented between 1704 and 1799 at universities throughout northern and central Europe, and especially at Edinburgh, which contributed eight between 1731 and 1787, more than any other institution.Whistler’s and Glisson’s medical treatises on rickets both refer to autopsies conducted on rickets sufferers, although neither says how many bodies were examined. Their most likely source of corpses with known clinical histories were the well-off patients they themselves, or their acquaintances, treated, when consent was forthcoming from parents, as from Evelyn for his liver-grown child.Whistler declares that rickets is a disease of infants, a term then usually meaning children under 2 years of age, with onset between the first year of life and the fourth. Neonates are within his purview, for he declares that rickets is invariably fatal to children suffering from rickets at or before birth. He refers to rickety children being unable to stand, which in the modern world is expected of a normally developing child between 7 and 17 months old, according to the World Health Organisation’s motor milestones.Whistler and Glisson also make some observations on the social status of those affected by rickets, in giving their opinions on its dietary causes. Whistler understood rickets to be a disease of the rich and the poor, but less of the middling sort who he believed to be more moderate in diet. Glisson concerns himself almost entirely with the wealthy, among whom he thought rickets most prevalent. Whistler and Glisson’s remarks are particularly noteworthy for what they tell us about seventeenth-century infant and child feeding practices.Glisson discusses infant feeding practices in the context of why children are susceptible to rickets at particular ages, declaring that breast-milk is the best food for newborn infants and that, by providing perfect nutrition, it protects them from rickets, all the while hinting that this was not a typical infant diet.Glisson takes it for granted that childcare is provided by nurses, as it would have been among his patients. He makes no mention of mothers’ involvement in any hands-on aspect of childcare: feeding, clothing and exercising infants are all portrayed as the nurse’s responsibility. The competence of nurses is questioned frequently, as when, for example, children are said to be over-clothed or swaddled (which would have reduced the amount of sunlight reaching the skin). The usual childcare method among the wealthy of early modern London was to hire a wetnurse, initially by sending the child away to the nurse’s home, although by the second half of the seventeenth century, nurses resident in the mother’s home were growing more common.Nurses did not always feed their charges breast-milk, or indeed any kind of milk. Mrs Wright’s eighteenth century medical advice is illuminating on the continuing perceived superiority of meat. As she explained: ‘It sometimes happens, that wet nurses have not enough of milk for their nurselings, and make up their food with bread, tapioca, or Indian arrow root, and the common milk of this town; we believe, that in general, beef tea, mutton or veal broth, mixed with them, is preferable’.In the seventeenth century, there was an accord between increased medical interest and surveillance of rickets and statistical evidence of its presence, but this unusual consensus fell apart when the disease no longer seemed lethal to contemporaries. Rickets was not subsequently used in the nineteenth century as a certified cause of death, and in that period it has been described as a hidden disease precisely because despite its high incidence it was not regarded as lethal, attracting little public health concern, a reversal of the seventeenth-century reaction to the disease.An important consideration in why particular cause of death descriptors are used is the balance between newness and familiarity, and the contextual knowledge of the reporter. A childhood disease must have needed to be common enough and distinctive enough for carers to see the same symptoms repeatedly before it was named and adopted by the Searchers as a cause of death. Conversely, symptoms that are very common eventually cease to seem noteworthy unless their dangers are immediate . When a disease becomes ubiquitous, we may have trouble perceiving its outward manifestations at all. The present global obesity epidemic offers an example of this phenomenon.The circumstances of the seventeenth-century fatal rickets epidemic that was apparently peculiar to England, and London in particular, also demand explanation, and this has been the main motivation for this article. There were sufficient fatalities of this apparently new disease among the children of wealthier citizens to induce a medical enquiry, and evidence of pre-nineteenth century rickets among Londoners of all social classes survives in statistical records, osteological remains and contemporary medical observations.This early rickets epidemic attests to the fragility of infant and child health in response to adverse conditions in England that were in this case largely anthropogenic, tipping the precarious climatic availability of Vitamin D at high latitudes into unavailability through urban air pollution from the new dependence on coal as a fuel in the growing metropolis, not yet accompanied by the technology to burn it more cleanly. This was exacerbated by deficient infant diets. Rickets-induced hypocalcaemia, convulsions, or additional nutritional deficiencies causing scurvy, could genuinely be lethal. Other child deaths attributed to rickets were likely recorded by the Searchers as such because of attention-grabbing deformities, especially to the head, while increased susceptibility to infectious diseases, and respiratory disease in particular, were more probable true causes of death. In the eighteenth century as well as the nineteenth, rickets morbidity almost certainly contributed to whooping cough mortality.In the section ‘The epidemiological evidence’ we saw that a much higher proportion of rickets deaths could occur from rickets in a rich parish like St Michael Cornhill than a poor one like St Giles Cripplegate, and contemporary medical authorities affirm that rickets was particularly prevalent among the wealthy. Two aspects to the unequal experience of rich and poor children with rickets have been identified. Firstly, given the age incidence of rickets in children of differing status confirmed by osteological evidence, rickets affected rich young infants earlier and more severely. Differences in feeding regimen by social status supply the most likely reason for nutritional deficiencies of calcium and perhaps Vitamin C, over and above deficiencies in Vitamin D induced by smog-related lack of sunlight experienced by all Londoners. Unlike poorer women, high status women did not usually breastfeed their own infants, and in consequence their infants were less likely to be fed exclusively on breast-milk. Secondly, where rich children survived, their recovery was better, so that few past the age of 2 years could plausibly be thought to die of the disease even when rickets was thought more lethal. Nutritional status may be implicated in this difference too. Richer families could afford to set their tables with more varied produce, so those of their children who survived weaning could access a wider range of nutrients, promoting faster recovery. Another reason for the difference in recovery of high status children may relate to their chances of escaping the city smog and experiencing sunlight outside London, at least periodically, on recreational excursions outside the city, while visiting family members, or staying in countryside residences. While in London, children who lived with richer families were also more likely to live on the wider main streets rather than densely packed and shaded courts or alleys. A limiting factor for outdoor pursuits of all children who suffered from rickets in early childhood was the difficulty and delay in walking unsupported. But for the well-off, there were servants or nursemaids to carry them about, supportive clothing, and even go-carts, mechanical contraptions devised to aid stumbling steps. Such recourse would not have been available to poor children, who were more likely to remain housebound until they were able to walk unaided.By weakening resilience, environment and nutrition contribute to morbidity and mortality above and beyond the number of fatalities that can be observed directly. Just as rickets seems to have paved the way for the emergence and rise of whooping cough in eighteenth century London, environmental and nutritional factors more generally have an impact on the incidence and lethality of infectious disease, then responsible for the majority of deaths, especially in cities. Much of what we now know of seventeenth-century rickets stems from a concern for the health outcomes of wealthy children, for whom micronutrient deficient infant feeding practices were probably the most significant casual factor, given the likelihood of opportunities to escape urban air pollution, at least periodically. Scrutiny of infant and childhood diets and recognition of their importance to health, as evinced in seventeenth-century physicians’ investigations of rickets, albeit as yet unaccompanied by clear advice or consensus on what constituted a good diet, has far-reaching implications. Through gradual shifts in attitude to child feeding and awareness of its importance, there was the potential for the well-off to overtake the rest in morbidity outcomes, leading to new social gradients in mortality yet to come.This work was supported by the Wellcome Trust, reference 360G-Wellcome-103322_Z_13_Z


The purpose of the paper is to create a multidimensional talent management model with embedded aspects of artificial intelligence in the human resource processes to increase employees' engagement and performance of the enterprise. The research was implemented on a sample of 317 managers/owners in Slovenian enterprises. Multidimensional constructs of the model include several aspects of artificial intelligence implementation in the organization's activities related to human resource management in the field of talent management, especially in the process of acquiring and retaining talented employees, appropriate training and development of employees, organizational culture, leadership, and reducing the workload of employees, employee engagement and performance of the enterprise. The results show that AI supported acquiring and retaining a talented employees, AI supported appropriate training and development of employees, appropriate teams, AI supported organizational culture, AI supported leadership, reducing the workload of employees with AI have a positive effect on performance of the enterprise and employee engagement. The results will help managers or owners create a successful work environment by implementing artificial intelligence in the enterprise, leading to increased employee engagement and performance of the enterprise. Namely, our results contribute to the efficient implementation of artificial intelligence into an enterprise and give owners or top managers a broad insight into the various aspects that must be taken into account in business management in order to increase employee engagement and enterprise’s competitive advantage. Thus, tArtificial intelligence mimics the ability of the human brain to learn, analyze, and make decisions . JabłońsThe biggest challenge in implementing artificial intelligence is changing the enterprise’s culture and leadership, acquiring new knowledge and skills, and changing business processes . AI in tThe first step towards expanding the use of AI among enterprises is to raise the level of awareness of how AI will have a positive impact on their business in the future . Also, tAI helps analyze the profiles of different candidates, where it checks whether the candidates have the required competencies. It also helps with communication by sending automated emails to candidates. With the help of artistic intelligence, employers get an in-depth set of required knowledge and skills, thus helping to select potential employees in acquire talent in a much faster time . TechnolH1: AI supported acquiring and retaining talented employees have an effect on performance of the enterprise.H2: AI supported acquiring and retaining talented employees have an effect on employee engagement.Despite the advantages that artificial intelligence offers for performing mentally demanding work, the evaluation of an investment in artificial intelligence needs to be evaluated appropriately . An enteH3: AI supported appropriate training and development of employees have an effect on performance of the enterprise.H4: AI supported appropriate training and development of employees have an effect on employee engagement.New ideas, new views on production or products, and how employees work bring enterprises opportunities to compete more successfully. Each team can develop creative processes for themselves that help them improve efficiency and better solve tasks, leading to an increase in employees’ work engagement . With thH5: Appropriate teams have an effect on performance of the enterprise.H6: Appropriate teams have an effect on employee engagement.For an enterprise to be ready for the future, its leaders need to create an innovative organizational culture. Organizational culture is key to building an artificial intelligence-driven enterprise . EnterprMoreover, artificial intelligence chatbots help enterprises engage their employees and maintain a positive and inclusive work culture regardless of background. This helps bring people together by creating an open environment for all employees, not just those closest to senior management . It is iH7: AI supported organizational culture has an effect on performance of the enterprise.H8: AI supported organizational culture has an effect on employee engagement.One of the main obstacles to adopting artificial intelligence is the lack of leadership support for artificial intelligence initiatives. Realizing the business value of investing in artificial intelligence requires leaders’ genuine understanding and commitment to drive far-reaching change . The impH9: AI supported leadership has an effect on performance of the enterprise.H10: AI supported leadership has an effect on employee engagement.Today, the introduction of AI in business human resources processes requires a new symbiosis between human resources, technology, and employees, as it affects the enterprise’s work tasks and business processes . ArtificH11: Reducing the workload of employees with AI has an effect on performance of the enterprise.H12: Reducing the workload of employees with AI has an effect on employee engagement.Today, artificial intelligence offers excellent value in a market where people are developing artificial intelligence systems to perform complex tasks . New artH13: Employee engagement has an effect on performance of the enterprise.The main survey involved randomly selected 317 medium-sized and large Slovenian enterprises. From each enterprise, a manager or owner participated in our research. Data were collected from April 2022 to the end of June 2022. Random sampling was carried out from the population, where the sample frame is represented by the AJPES (Slovenian Business Register) database of business subjects . EmpiricWe used a questionnaire which was closed type a 5-point Likert-type scale. The questionnaire was translated into the Slovenian language. Items for construct AI supported acquiring and retaining a talented employees were adopted from We tested the hypotheses with the SEM and used the software tool WarpPLS 7.0. The WarpPLS 7.0 program was used to verify the existence of effects between constructs. We decided to use WarpPLS 7.0 program because it offers many advantages and unique solutions compared to others. We see one of the key advantages in the possibility of explicitly defining non-linear connections between pairs of latent variables . As partIn addition to the results in p < 0.05; AR → EE = 0.443, p < 0.05), AI supported appropriate training and development of employees , appropriate teams , AI supported organizational culture , AI supported leadership  and reducing the workload of employees with AI  have an effect on performance of the enterprise and employee engagement. Also, employee engagement has an effect on performance of the enterprise . Thus, we confirmed hypotheses H1–H13.The results in Moreover, for an enterprise to become ready for the future, its leaders must create an innovative organizational culture . OrganizThe implementation of artificial intelligence in an enterprise is a comprehensive change of the enterprise’s processes and may lead to greater productivity, growth and competitiveness of the enterprise. The use of AI technology offers new business opportunities to enterprises, greater productivity, new ways of designing business models of enterprises, encourages innovation and development, and new ways of promoting. From this point of view, we have developed a multidimensional talent management model with embedded aspects of artificial intelligence in the human resource processes to increase employees’ engagement and performance of the enterprise. The research model highlights the importance of certain aspects that are necessary for the successful operation of an enterprise in today’s rapidly changing environment. Thus, regardless of the size of the enterprise, the following aspects must be taken into account when implementing artificial intelligence to increase performance of the enterprise and employee engagement: AI supported acquiring and retaining talented employees, AI supported appropriate training and development of employees, appropriate teams, AI supported organizational culture, AI supported leadership and reducing the workload of employees with AI. The development of a digital society and the digitization of the economy requires appropriate legislation and an environment that will encourage the development of digitization and digital entrepreneurship. It is necessary to facilitate access to financial resources for enterprises, especially for SMEs, so that they can more easily access funds for financial investment in technological development, digital transformation, artificial intelligence, knowledge and skills, which will help them to be more competitive in Slovenia and in the international business environment.Our study is limited to a sample of managers/owners in Slovenian enterprises. Limitations of our research are reflected in the size of enterprises because we selected medium-sized and large enterprises. The results show the situation of medium-sized and large enterprises and do not provide conclusions for small enterprises, especially in terms of whether the use of AI is suitable for small enterprises. The challenge faced by micro, small and medium-sized enterprises (SMEs) is certainly the fear of changes brought about by digitization and digital transformation of enterprises. When dealing with challenges, SMEs often have insufficient information, financial resources and personnel who have the appropriate skills for the digital transformation of the enterprise. The limitations of our research are also reflected in the constructs that we have chosen for the survey. Therefore, we recommend further research to develop new constructs for example, implementation of management information system into the enterprise, adopting AI technologies, using AI solutions in a project, enterprise’s competitiveness and analyze them through structural equation modeling. Also, for further research, we suggest the examination of constructs that we have chosen for the survey in other countries to compare the results.Artificial intelligence has taken over the enterprise sector and changed the way enterprises do business today. Thus, the new advancing trends like artificial intelligence and other cutting-edge technologies are transforming the way of work, changing the workforce’s profile. The paper highlights the important constructs for successfully implementing artificial intelligence applications in the enterprise to increase employee engagement and performance of the enterprise. The main highlights that enterprises need to be aware of when implementing artificial intelligence are improving employee engagement and productivity, gaining knowledge in the field of artificial intelligence, and increasing an enterprise’s profitability. Artificial intelligence is becoming part of the digitization strategy as it enables enterprises to leverage vast amounts of process data with advanced algorithms to improve efficiency and reduce production costs. The use of artificial intelligence in production will be especially increased for quality control. Artificial intelligence is very promising for visual inspection of parts at different stages of the product development process and in all workplaces, including production and assembly, with the aim of achieving a certain quality. As the demand for innovative products increases rapidly, the use of artificial intelligence is becoming essential to understanding customer needs, requirements, and desires.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. Written informed consent from the patients/participants or patients/participants legal guardian/next of kin was not required to participate in this study in accordance with the national legislation and the institutional requirements.All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.This work has been fully supported by Croatian Science Foundation under the project UIP-2020-02-6312. The authors acknowledge the financial support from the Slovenian Research Agency .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.


Despite efforts to ensure equitable quality of care for all patients, a significant gap persists between the quality of care experienced by insured and uninsured patients in Saudi Arabia. This study aims to identify and compare the differences between insured and uninsured patients in terms of their experience of quality of care in a tertiary hospital.  A descriptive cross-sectional study was utilized. Insured and uninsured individuals who had undergone identical medical procedures in early 2021 were identified from a public 500-bed tertiary hospital. About 350 patients participated in this study by completing an online, self-administered questionnaire, adopted by Abuosi and others in 2016, assessing six dimensions of quality of care. p=0.001). While insured group reported high quality of care, followed by fairness of care , uninsured subjects experienced less fairness with low quality of care.  Significant differences were reported between the quality of care experienced by insured and uninsured subjects (M = 3.37, SD = 0.525, and M = 3.06, SD = 0.452, respectively,  The insured individuals were found to be more attentive to the quality of care offered by the hospital than their counterparts. Efforts to close the gap in quality of care should include monitoring healthcare outcomes, adopting transparency standards, and facilitating procedures to minimize barriers among patients. To reduce the quality chasm among society, quality of healthcare is primarily one of the cornerstone strategies implemented by health organizations worldwide . Global According to the Institute of Medicine, the degree to which high-quality of health services are provided by increasing the level of the preferred health outcomes is collectively defined as quality of care . PreviouHealth-care stakeholders have sought to identify the dimensions and factors by which quality of care is measured , 18. WhiThe complex nature of quality emphasizes the need to measure different experiences of quality of care in health institutions for all sorts of medical episodes. Indeed, Atinga and Baku stressed that the level of commitment to the quality of care in developing countries is low because of the existence of many socio-political restrictions that prevent the achievement of the required level of quality such as the existence of financial and human constraints . Levels Health insurance is a method of protection against the risks of illness or injury through the provision of urgent medical care to all individuals who need it as well as compensation against temporary disability. Other studies have emphasized that health insurance is a social economic organization whose purpose is to facilitate medical service without financial impediment  as a barrier between the individual and his/her access to the service , 27. ConGlobally, health insurance is proposed to be the most appropriate way to deal with the increasing cost of medical care. Abuosi emphasized that the acquisition of health insurance provides many advantages, but the degree of these advantages varies in both developed and developing economies . FocusinAgain, Ellis argued that increasing the volume of economic investments in healthcare, the emergence of new technologies, the development of medical technology, which is reflected in the cost of health services, and the increased cost of medicine all contribute to the increase in the cost of healthcare . As suchIn light of the above, it can be proposed that the essence of health insurance is the achievement of the principle of social solidarity among individuals since each one should be treated according to the medical necessity. Health insurance is one of the economic pressures on both communities and individuals . PreviouAbuosi noted that there were insufficient studies regarding health insurance and quality of care and argued that previous studies that linked health insurance with the quality of care have different results. Some studies showed that health insurance leads to an improved quality of healthcare . For exaIn addition, Nguyen and colleagues found in their Ghana-based study that although insured individuals paid for medicine and tests not included in the national health insurance scheme, they would controversially pay less compared to uninsured individuals. Other studies have proven that there is a negative impact of health insurance on the quality of care . For insIn contrast, others found that both insured and uninsured patients had positive experiences toward the technical quality of care, while they had negative experiences toward providers . Other sth worldwide for a long time, but no other report was issued as there was a controversy about the methodology of the report [In SA, government has paid special attention and priority to the healthcare sector. As a result, health services have witnessed remarkable progress over the previous ten years. The World Health Organization (WHO) has confirmed that the healthcare system in SA outperforms many other international health systems, such as Australia, and other Arab health systems, such as the UAE and Kuwait. SA's health-care system was ranked 26e report . Despitee report .Currently, the Ministry of Health (MoH) is the main funding provider for the healthcare system in SA. Precisely, Yusuf highlighted that the most important challenge facing the MoH is the financing of health services . She poiTherefore, the overriding objective of this study was to compare the experiences of insured and uninsured patients in terms of the experienced quality of care while attending identical medical episodes at a tertiary hospital in SA.This is a descriptive cross-sectional study design describing wide experiences of healthcare provided to insured and uninsured patients based on a reliable and valid self-administered questionnaire.This study was conducted in a 500-bed facility with all medical and surgical services for insured and uninsured patients. An electronic survey (web-based) (Google docs) was emailed to particular patients admitted in the hospital and discharged within 24 hours, via patient affairs and the head nurses. The process of data collection was limited to adult patients admitted between January and May 2021. Through online survey, the questionnaire was written in Arabic and English languages. Participants completed the questionnaire, and the results ended in the principal investigator's email, but without identification of who was the subject.To be legible in this study, the adults should experience identical medical episodes (whether insured or uninsured), especially in terms of procedure and treatment plan. The random-quota sample technique was conducted in specialized clinics to collect an equal number of responses, which means choosing the subject according to a specific quality. A total of 622 electronic forms were first emailed to the identified respondents by the nursing department and patient affairs.Six dimensions of quality of care were compared among two groups . The measurement was based on 5-point Likert scale ranging from 1, very poor, to 5, very good. The instrument, adapted in this study, was developed and applied in Ghana by Abuosi and others in 2016 . The insT-test, analysis of variance (ANOVA), Kruskal–Wallis test, and Mann–Whitney tests to measure the differences between groups. Correlation (Pearson correlation coefficient = r) test was used to detect the relationships between variables and determine the strength of the overall relationships between items and their dimension. The p value, less than 0.05, was considered as a significance level.After data verification, they were coded, loaded, and analyzed using the SPSS program version (24.0). Descriptive statistics were used to compute means, variances, and standard deviations. Inferential tests were used like The sociodemographic characteristics of the participants are shown in t-test. Therefore, results indicated a significant difference between insured and uninsured subjects toward all quality experience dimensions for health-care services at the hospital , except in the fairness of care dimension.To find out the differences between insured and uninsured individuals toward dimensions of study, U-test. In both groups, there was a significant difference observed between males and females in their responses toward the adequacy of quality .To find out if there are any statistically significant differences between males and females in both insured and uninsured groups in their responses toward dimensions of study, To identify the correlation between quality experience dimensions, the Pearson correlation test was performed. p ≤ 0.05).The main objective of this study was to explore equity when receiving similar medical services based on specified quality of care standards among insured and uninsured patients attending one setting. Approving a concern of the quality of care inequity, the results showed that insured individuals largely received a self-reported high to moderate levels of care than their counterparts , 33. As Attracting more insured patients by implementing the quality management approaches, insured individuals were contented with services and resources offered by the hospital as it is adequate, available for integrated medical service, have a moderate level of quality, and served by qualified health-care professionals . HoweverIn indicating that uninsured individuals received a lower level of care than insured ones, there was a dissatisfaction where uninsured persons were subjected to prolonged waiting periods, payment procedure, and a difference in treatment compared to insured patients –42. On tThe study was conducted in only a tertiary hospital in Riyadh, which may limit the generalization of results. Another study in public health facilities may offer enough representation in both public and private hospitals. There is no guarantee that both groups underwent the exact procedure since the setting was not fully adopting the international classification of disease. More efforts from managers were needed to be practiced to reduce the quality chasm among individuals.Moderate quality experience was demonstrated by both insured and uninsured groups; however, insured people reported higher level of experiencing quality of healthcare in a tertiary hospital than uninsured patients. The perceived quality of healthcare is pivotal in assessing quality of care for individuals. Recommendations to healthcare providers to integrate quality for both insured and uninsured can lead to improved health status and holistic welfare of society.


Most Air Traffic Controllers (ATCOs) must cover uninterrupted work shifts for 24 h a day, seven days a week. The proper planning of a shift schedule requires consideration of at least three elements: the specific characteristics of the controller task, the physiological needs of the operator, and the definition of rest periods within rostering. We reviewed the literature for providing comprehensive guidance on the main requirements for the construction of a shift schedule for ATCOs. Our considerations are organized according to a rationale reflecting the most important criteria for the construction of the schedule: namely, the organization of rest periods conceptualized as intervals between cycles of shifts, intervals between individual shifts, and breaks within the shift. The suggested parameters could be used to construct shift schedules within a variation margin that depends on individual contexts of application. Most Air Traffic Controllers (ATCOs) must cover uninterrupted work shifts for 24 h a day, seven days a week. In these operational contexts, fatigue can adversely affect performance by increasing response time and the number of errors ,2,3. AddThree elements contribute to creating a fit and safe shift planning. The first is related to the specific characteristics of controller tasks, which usually reflect different levels of complexity and, therefore, require varying amounts of effort. The second element is the physiological need of the operator, which varies according to individual differences. Task characteristics and physiological needs greatly affect the third element, which is the organization of rest periods.Based on different information sources , air traffic controllers must manage a complex, dynamic, and time-constrained traffic situation to identify and solve potential conflicts and optimize the flight paths without impacting safety. Therefore, they must perceive, comprehend, and anticipate multiple characteristics and flight paths of many aircraft while new incoming aircraft create new traffic geometry for evaluation. ATCOs’ diagnosis, decision making, and action implementation are based on these insights into current and anticipated structures of the changing situation. These types of tasks may require maintaining a high level of attention and engagement for an extended time and for specific actions to discriminate against the presence of target stimuli, typical features of a vigilance task. Studies conducted on performance in supervisory tasks indicate a decline in performance after a short (ranging from 20–30 min) ,11 or moThe most influential variable inherent to individual characteristics is represented by changes in biological rhythms that occur during work over a 24-h period ,17. The The third element is the focus of this review and is the management of breaks during shift work. Although several studies address shift workers (see below), at least two problems have prevented a definition of guidelines for the design of ATCOs’ shift schedules. The first problem is related to the generalization of the shift worker figure; numerous studies summarize information obtained on different professional categories, such as chemical employees , health The objective of this review is to integrate those studies with the aim to provide comprehensive guidance on the main requirements for constructing a shift schedule for ATCOs.An extensive though not systematic search conducted on major databases  allowed the identification of relevant studies for this literature review, combining the keywords “shift working” or “shift rotation” and “air traffic controllers”. Only English written peer-reviewed articles were selected. Considering the narrative nature of this review, we considered any information we came across to be valuable and no interval dates were set. The articles were first screened for relevance by reading the title alone and then filtered by reading the abstract. Ninety-six full-text articles were included in this analysis.The results are organized according to a rationale reflecting the main requirements for the construction of the schedule: namely, the organization of rest periods conceptualized as intervals between cycles of shifts, intervals between individual shifts, and breaks within the shift.The shift scheme is one of the most critical features in defining rest periods within a shift cycle. Relevant information on this issue comes from a 2006 report by EUROCONTROL , the intShift duration is a factor that has been studied by several researchers, both in laboratory and in various work settings . The durations typically considered vary between 8 and 12 h. Twelve-hour shifts have been shown to have several advantages, including allowing more days off during the week ,25 and gTwelve-hour shifts, however, also have disadvantages. Some studies have found increased fatigue in 12-h shifts  and decrWhen choosing between a 12-h shift and an 8-h shift, another aspect must also be considered: while there is no evidence that having more time to rest is sufficient for a full recovery, on the contrary, the long-term adverse effects of fatigue accumulation are well documented ,50. In lA review published by Fischer, Lombardi, Folkard, Willetts, and Christiani  considerDespite the relevance of this issue, few studies have considered the distribution of rest periods within a cycle of irregular shifts. Below, we present several studies conducted on specific categories of workers other than ATCOs. Interesting results are provided by the work of Folkard and Tucker , who conÅkerstedt and colleagues  sought tA study by Totterdell and colleagues  also souA further variable to consider is the presence of shifts that include night hours, with consequent accumulation of fatigue due to changes in biological rhythms. Knauth, Rutenfranz, Herrmann, and Poeppl  performeA study by Cruz and Rocco  focused The reduction in sleep hours in conjunction with a service period that includes night hours increases when a roster provides for multiple consecutive night shifts. A study by Härmä and collaborators  investigThe same conclusion was reached by Folkard and Tucker  in a revDespite a moderately pronounced effect, the authors report the absence of data useful to explain this phenomenon. Indeed, the studies analyzed showed a clear increasing trend in the relative risk of incidents following consecutive night shifts, but there is insufficient information to explain this effect. A possible interpretation lies in the loss of sleep associated with the performance of a service that includes night hours, which accumulates when multiple shifts are worked out at night in succession, without the availability of a night to be able to recover from sleep loss. In the same study and using the same methodology, the authors also compared four consecutive daily shifts to determine whether the increased risk was due exclusively to the night shift or, in general, to the succession of shifts. The results showed a slight increase after four consecutive day shifts. The proportion of the incident risk was approximately 2% more on the second day, 7% more on the third day, and 17% more on the fourth-day shift than on the first day.The comparison of these studies demonstrate that the increase in risk of incidents is greater after consecutive night shifts than when subsequent shifts are daytime. An additional risk in performing consecutive night shifts is the so-called “night shift paralysis”, reported by several ATCOs and described as a short-lived but disabling paralysis that occurs during the night shift, when workers must maintain a state of wakefulness despite the pressure of sleep. This phenomenon was reported by 6% of a group of 435 ATCOs in a survey conducted by Folkard and Condon  and was The results reported so far refer to the rest period available following consecutive cycles of shifts, whether day or night. However, the accumulation of fatigue also depends on the amount of rest available between individual shifts, understood as the time between the end of one shift and the beginning of the next. This interval is typically variable, and its reduction typically results in a corresponding reduction in the duration of sleep. One way to allow the operator to avoid an accumulation of sleep loss is to identify the interval between two shifts necessary for sufficient rest.A series of studies commissioned by CAMI in 1999 collected information on this issue involving ATCOs. The objective of the research program was to monitor sleep, mood, fatigue, and cognitive performance in a group of controllers to assess the association between these factors and the shift system. As reported by Nealley and Gawron ,63, evenquick return. In a review on the topic, Vedaa and colleagues [A shift interval of fewer than 11 h is also called a lleagues  found a lleagues  reportedlleagues ,66,67 anlleagues ,68,69. Tlleagues  and causlleagues . The stulleagues  also repRoach, Reid, and Dawson , on the The tendency for individuals to engage in domestic, family, or leisure activities during the day increases their sleep loss after a night shift. This aspect directly refers to the personal well-being that arises from the balance between time spent at work and time spent with family and friends . A report published by EUROCONTROL  recommenIt is worth pointing out that the opportunity to recover sleep hours also has a utility in a preventive perspective since prolonged sleep limitation can have effects on the brain that can continue to affect alertness and performance for days or weeks . DespiteThe EUROCONTROL study  suggesteOne feature that determines the minimum duration of rest is the ability to fall asleep and recover from sleep loss. In this regard, the study by Härmä and colleagues  examinedÅkerstedt and colleagues  producedIn many cases, the information available in the scientific literature on this topic appears to be contradictory. A possible explanation is due to the different nature of the work, as suggested by Tucker . FolkardChang, Yang, and Hsu  conducteAn analysis conducted by Folkard and Tucker  recommenThe data from the literature agree with the importance of breaks to allow for a rest during the working day. However, no homogeneous indications about the rest break timing are available. There is conflicting evidence regarding the optimal duration of breaks, and it seems likely that both the optimal schedule and the beneficial effect of rest breaks depends on the work’s features .Studies carried out in ATM contexts confirm that rest breaks should be adapted to the characteristics of the activity being carried out by the operator. Activities carried out by ATCOs require constant vigilance, and since performance in supervisory tasks decreases over time, a break is necessary every 2 h of continuous work ,80. MoreThe results suggest the validity of short sleep to improve performance, especially during night shifts. In this case, the duration should be at least 2 h over an 8-h night shift. The New Zealand study was an 8-month field study . PhysiolDuring rest breaks, ATCOs should have time to move away from their working position, have a washroom break, or spend time in facilities for relaxation at work ,80. SeveAnother relevant aspect is the time when the break is scheduled. A study by Chang, Yang, and Hsu  comparedA further element to consider is the relationship between performance and changes in air traffic, which was also analyzed in a study published by Hagemann , who invThis review attempted to extract guidelines to design a shift schedule for ATCOs. The aim was to provide appropriate advice in choosing parameters for the definition of rest periods. The results were presented following a descriptive logic of the main parameters emerging from the literature. The interrelation of these parameters does not allow for the creation of a list with clear directions. Rather, it is plausible to provide indications that may justify the choices in constructing a schedule of shifts. An example is the maximum duration of a shift, which could vary between 7 h and 10 h. The indication is to stay within this range, but the choice depends on other parameters of the schedule desired for use. A longer rotation, for example, of 6 days, may involve shorter shifts, with a broader interval between two shifts and several little breaks within the shift. On the contrary, a more compressed schedule will provide longer shift duration, with a shorter interval between two shifts, but a wider gap between two programs and, of course, a different distribution of breaks within the shift. Shifts that include night hours have more significant implications for the operator’s perceived fatigue as a result of the loss of sleep that occurs both during the shift and during the rest of the day due to the predisposition toward wakefulness during the daytime hours . Based oFatigue in air traffic management is an inevitable hazard and ANSPs are keen to address its safety implications. ICAO  and EASA (see the EC 217/373) recommend the development and implementation of a Fatigue Risk Management System in recognition of the issue’s relevance, and to provide the ANSPs with guidelines and policies to mitigate the fatigue risk.In this framework, future research on professional fatigue may play a significant role, supporting the ATS providers in defining a proactive evidence-based approach to fatigue management.Particularly, sleep science may contribute to the development of an integrated approach to fatigue: identifying evidence to improve physiological and behavioral knowledge on how to recover from sleep loss (across one night or multiple nights of shift) or how the circadian body clock affects the timing and quality of sleep (and then performance). Moreover, research on fatigue is expected to also contribute to support the ATS providers in developing reliable tools for monitoring the fatigue of ATCOs, by considering relevant indicators.Currently, the way to manage fatigue in the European ANSPs remains fragmented and the monitoring approaches implemented are quite different across ANPSs. Research efforts in this field may contribute to the harmonization process of fatigue management.This review does not discuss the implications of recent technological ATM innovations. The Remote Tower Center (RTC), for example, requires an air traffic controller to work in “multiple positions”, which means handling two or more airports from one remote tower module. The maximum number of airports assigned to one controller, the maximum number of movements per controller, and the maximum number of controllers per airport are only a few examples of the resulting implication of designing an efficient roster plan in an RTC. However, research is ongoing and this novelty has not yet been fully addressed in the literature. Future reviews should also approach this major change.In conclusion, this work represents an attempt to provide directly transferable information in defining shift schedules for ATCOs. The indications identified have made it possible to partially achieve the objective of the work. The suggested parameters can help construct shift schedules within a variation margin that depends on individual application contexts. The definition of specific parameters remains somewhat abstract and open to interpretation, thus representing a work limitation.


In recent decades, the US bank market has been exposed to several waves of mergers, resulting in concerns about branch presence and consumer access to financial services. This paper examines the effects of bank mergers on branch density in the period 2000–2020. To do so, we use panel regressions and matching techniques at the census tract level to study the impact of inter- and intrastate mergers before and after the Great Recession of 2007. To generate plausible exogenous variation for mergers, our analysis focuses on transactions involving large entities, and we consider the within-tract variation in exposure to mergers. A comparison of exposed and unexposed tracts shows that in the period under study each merger  reduced branch density by around 3%. Moreover, interstate mergers reduced branch density at the tract level across the whole period but had an expansionary effect on the number of branches at the county level before the crisis. Intrastate mergers, in contrast, had a consolidation effect across the whole period, an impact that was more intense in rural tracts and in tracts where merging entities operated overlapping branch networks. Finally, we show that the reduction of bank branches was stronger in tracts with a relatively higher penetration of broadband Internet services, but we find no evidence that the adoption of FinTech services intensified branch closures. Riegle-Neal Act of 1994, favored the expansion of banking entities into other states and contributed to the increase in the number of bank branches. This situation was reversed after the 2007–2008 financial crisis and the Great Recession. Between 2009 and 2020, fifteen per cent of branches were lost nationally, a trend that is set to continue in the years ahead due to the increasing digitalization of the banking sector, the emergence of FinTech services and changes in consumer habits in the wake of the coronavirus pandemic. Urban areas have suffered high levels of closures and ‘banking deserts’ are today familiar features of rural areas. All in all, this process has raised concerns that a growing number of households and businesses might be losing adequate access to financial services. Branch closures increase consumers’ financial services costs, such as cashing checks, obtaining loans or simply opening deposit accounts. They are, moreover, forced to travel longer distances to contract such services, while losing the personal advisory services they received from their traditional bank tellers due to staff reorganizations. An additional concern is that this process of ‘financial exclusion’ may be more intense in areas with higher proportions of low-income families and minorities, groups that frequently have limited mobility and lower rates of Internet access . Tract-level demographic and socioeconomic variables are taken from the US Census Bureau.One obvious difficulty in estimating the effects of mergers on branch closures is that a merger might be influenced by the prevailing economic conditions of local markets. To address this possibility, we estimate a fixed-effects model that analyzes the impact of mergers on branch closures and openings at the census tract level. Following Nguyen , our estOur results indicate that during the period 2000–2020 each merger between large banks reduced branch density by 3% in those tracts in which the acquired bank had a presence and that this effect increased up to 6.5% in those tracts in which the acquirer and the targeted banks had overlapping branch networks. Interstate mergers reduced branch density by 2.7%, while intrastate mergers reduced the density by 4.5%.de-branching policy and by 2020 the number of branches had fallen to 85,050. Interstate mergers contributed to this adjustment at the tract and county levels and in tracts with overlapping branch networks, the density fell 5% in comparison with that in unexposed tracts.In the years before the Great Recession and in the first decade of the new century, branch density increased notably across the USA. While in 2000 there were 85,492 bank branches, by 2009 this number had climbed to 99,550. In this period, interstate mergers had an expansionary effect and branch density increased in the affected counties; but, in tracts directly exposed to mergers, the increase in branch density was not so great. This outcome reflects the consolidation behavior adopted by the acquiring entities, especially in tracts with overlapping branch networks. After the crisis, banks initiated a major Intrastate mergers, meanwhile, had a negative effect on branch density both at the tract and county levels across the whole period under study. More specifically, after the financial crisis, intrastate mergers had a strong impact on rural tracts and tracts in which the merging banks had overlapping branch networks. Thus, large bank mergers reduced branch density by 14% in rural tracts and by 12.6% in tracts with network overlaps.Our paper also shows that, over the last decade, the consolidation effect of mergers has been stronger in tracts with a relatively higher penetration of broadband Internet. This outcome suggests that online banking serves as a substitute for brick-and-mortar branches and that the deployment of high-capacity telecommunication networks can accelerate the closure of bank branches.5Several papers have analyzed the branching strategy of banking entities in the USA. While some authors have focused on the effects of branch competition on prices Sapienza , others The main contribution of our study to this literature is to show the heterogeneous impact of mergers on branch deployment across different periods and different types of socioeconomic area. Specifically, we examine the impact of large mergers during pre- and post-crisis periods at the tract level and analyze the differential effects for urban and rural areas. Additionally, we consider the differential effect of interstate mergers  and intrastate/inter-county mergers . We consider that inter- and intrastate mergers may have had different impacts because they had different motivations. While one of the objectives of the former was to expand into other markets , the objectives of the later were to generate efficiency gains and cost reductions.Riegle-Neal Act as an exogenous shock on bank competition and show how the competition resulting from these regulations reduced the share of unbanked households, benefiting those with lower income and living in rural areas. Other papers have shown that the distance between lenders and borrowers determines the availability of and the terms of credit, especially in low-income neighborhoods . The Act allowed both unrestricted interstate banking and interstate branching, which meant bank holding companies could acquire banks anywhere in the US and diversify their assets. The reform sought to increase the efficiency of financial institutions, permit the conversion of bank subsidiaries into bank branches and, thus, eliminate indirect costs  and the Reports of Structure Changes (ROC) provided by the Federal Deposit Insurance Corporation (FDIC). The SOD data are collected for all institutions insured by the FDIC, including commercial banks and savings and loans associations, and they describe the financial situation (deposits and assets) and bank specificities  at the branch level. The SOD data include details of the branches’ latitude and longitude, allowing us to geo-locate the branches on the map of census tracts using GIS software.We draw on a dataset for more than 72,738 census tracts located in 3090 counties in the 50 states of the USA and the District of Columbia for the period 2000–2020.The ROC data describe the non-financial activities of all entities insured by the FDIC, capturing institutional and structural changes including mergers, failures and new offices of financial entities.Density Population is the ratio between a tract’s population and its area. Income is the median family income in the tract. We also consider the percentage of population over 60 years (% older), the percentage of population with a college degree (% higher education) and the percentage of population that belongs to minority ethnic groups (% minority).Information on the socioeconomic characteristics and median family income at the census tract level has been collected from the US Census Bureau. We use information from the 2000 Decennial Census for the period 2000–2008 and from the American Community Survey (ACS) for the period 2009–2020. The Census also provides the tracts’ land area used to calculate population densities. Broadband Penetration, which captures the percentage of the population in the tract with a subscription to a fixed broadband Internet connection. Specifically, we use the variable “Residential Fixed High-Speed Connections over 200 kbps in at least one direction per 1000 inhabitants”, which has been obtained from the Federal Communications Commission’s Form 477, available for the period 2009–2018.Fintech Mortgage Lending, which shows the percentage of mortgage lending covered by FinTech entities at the county level, for the period 2010–2017. This variable only reflects one of the multiple services that might be offered by FinTech entities, but it serves as a good proxy of the relevance of these entities in local markets. This information has been obtained from Fuster et al.  and the implementation of new banking regulations , reduced the profitability of the banks and led to mergers aimed at reducing the costs of premises and improving efficiency :where Mergerskct is the number of times a tract has been exposed to a merger. In one year, tracts may be exposed to as many as three mergers; moreover, each tract can be exposed to several mergers over the entire span of the period. Note that a tract is considered as having been affected by a merger when the acquiring or the acquired bank was operating in the tract before the merger. Additionally, in several specifications of the model, we draw a distinction between interstate mergers and intrastate/inter-county mergers.In this model, the variable  Banks reflects the entry of new banks in the tract, which can have positive effects on the number of branches. This variable takes a value equal to 1 when a bank starts operating within the tract. HHI Deposits is a Herfindahl–Hirschman index (HHI) that measures the concentration of bank entities’ deposits at the tract level. We expect tracts with a high market concentration to have fewer bank branches. To account for the possible endogeneity of this variable, we include it in the model with a one-year lag. Savings & Loans is a variable that reflects the percentage of Savings and Loan institutions in the tract. These are banks that a priori are locally oriented and place stronger emphasis on residential mortgages, while commercial banks tend to concentrate more on businesses and unsecured credit services such as credit cards. Hence, we expect Savings & Loan banks to have more branches than their commercial counterparts. We also consider the Total Deposits kept by residents in the tract branches. The existence of a large volume of deposits in the tract should induce banks to create new branches to compete more effectively against rivals. The potential endogeneity of this variable is treated by including it with a lag.21The vector Population Density), median income (Income), percentage of population represented by minority ethnic groups (% Minority), percentage of population with a college degree (% Higher Education), and percentage of population over the age of 60 (% Older).Equation (1) also considers a set of socioeconomic variables that reflect the characteristics of the tracts, namely population density , tract-fixed effects (Tractk) and the interaction of county and year-fixed effects (Yeart ·Countyc).Finally, the model in Eq. (1) also includes year-fixed effects .in counties that were exposed to the merger of a large bank in the period under study. Column 1 reports the effect of all mergers on branch density, and column 2 shows the separate effects for interstate mergers and intrastate/inter-county mergers. Mergers reduced branch density in the exposed tracts by 2.8% in comparison with unexposed tracts. Our results for interstate mergers are like those found for all merger types. Tracts affected by intrastate/inter-county mergers presented a 4.5% reduction in branch density in comparison with untreated tracts. Columns 3 and 4 repeat the analysis, but the sample is now restricted to tracts that during the period under study were exposed to the merger of a large bank. This makes the group of tracts exposed and unexposed to a merger more comparable. The results for the impact of mergers on branch density are unchanged, confirming the conclusion that mergers, especially intrastate/inter-county mergers, had a negative impact on branch density.Below, we present the results of the fixed effects model examining the impact of mergers between large, multi-branch banks on branch density at the tract level. Table The results for the control variables in Table 22Riegle-Neal Act of 1994 banks used mergers as a mechanism to expand their activities to other states and that this led to an increase in branch density. This expansion effect could have been reversed after the 2007 financial crisis, as banks tried to reduce their costs by closing branches in less profitable local markets. To analyze the existence of this differential impact of mergers before and after the crisis, Table One of the hypotheses of our study is that after the Another interesting analysis is to consider the effect of mergers for very large banks. Table Population Density, % Older, % Minority, % Higher Education, Income). Specifically, we impose that the tracts exposed and unexposed to the mergers are similar in terms of these characteristics in all the years of the analysis. Moreover, our analysis considers all tracts in counties affected by mergers in the period examined. Table Table Table To evaluate the importance of mergers as a mechanism enabling banks to expand their activities to other markets, we next analyze the effects of mergers at the county level. Column 1 in Table tracts directly exposed to interstate mergers increased their branch density at a smaller rate than tracts unexposed to such mergers. This might be attributable to strategies of consolidation or could reflect the deterrence effect of mergers on rival banks. However, at the county level these mergers generated an increase in branch density. After the Great Recession, this expansionary effect was no longer present as both tracts and counties were negatively affected by interstate mergers. In the case of intrastate mergers between large banks, no evidence is found of an expansionary effect at the county level before the crisis. Indeed, both tracts and counties exposed to these mergers lost branch density with respect to unexposed tracts. However, after the crisis, we find that intrastate/inter-county mergers had a stronger impact.To sum up, these results imply that before the crisis To further evaluate the effects of mergers, we next consider those cases in which prior to the transaction the acquirer and the acquired banks had overlapping retail branch networks in the same tract. We expect that in tracts with a duplicate presence the merged entity will be more likely to close branches. Table These results confirm the hypothesis that the most intense branch consolidation effect took place following mergers in tracts in which banks had an overlapping presence before the transaction. The impact was particularly high in the case of intrastate mergers after the crisis. However, we also find a significant, albeit more modest, impact of mergers in tracts without overlapping retail branch networks. Finally, it is worth stressing that our results here are in line with Nguyen , who stuIn the last decade, the digitalization of the economy has allowed banks to offer many of their services online and this has favored the development of FinTech services. The rapid expansion of online banking has substantially reduced the number of customer visits to brick-and-mortar branches and has led banks to close their less profitable branches. Below, we re-estimate Eq. (1) to determine the impact of the adoption of fixed broadband Internet and FinTech services—which has been quite heterogeneous across the US tracts—on banks’ decision to close branches after a merger.Lending FinTech, as devised by Fuster et al.  indicate that in 2018 about 19% of the US population lived in rural areas, representing as much as 97% of the total land area. The delineation between urban and rural populations is based essentially on population density.24Panel A in Table Panel B presents our estimates for rural tracts. Our results show that mergers reduced branch density by around 2%, the impact being similar before and after the financial crisis. Interstate mergers of large banks only had a negative effect on branch density before the crisis but did not affect the number of branches after the crisis. In contrast, intrastate mergers reduced branch density by 8.6%. Before the crisis, these mergers reduced branch density by 5.2%, while after the crisis the negative effect increased to 14%.At the end of the 1990s, the deregulation of interstate banking and branching was seen as an opportunity for many large banks to expand their activities to other states. In a period of population growth and high demand for financial services, banks used mergers to enter new markets, as these allowed them to gain in scale, implement new technologies and management practices, and diversify their risk. Our analysis has shown that interstate mergers increased the number of bank branches in the counties affected by this expansion strategy. However, the tracts directly exposed to the mergers experienced a smaller increase in their branch density than that experienced by unexposed tracts. In the case of intrastate mergers, both the counties and the tracts directly exposed to the mergers experienced a smaller increase in their branch density than was experienced by unexposed counties and tracts. One explanation for this consolidation effect is the closure of branches in tracts in which the acquirer and the acquired entities had a duplicate commercial presence, yet branch closures also took place in tracts without overlapping branch networks. This suggests that mergers were an opportunity for banks to restructure their retail networks, and in addition mergers could deter entry in local markets.Following the 2007–2008 financial crisis, the decrease in the banks’ profitability due to the fall in demand and low interest margins led to branch closures, which helped the sector reduce its costs. The average number of inhabitants served per branch rose from 3067 in 2009 to 3874 in 2020, representing an increase of 26.5%. In this period, there was a marked growth in the number of mergers, which served to foster market concentration. Our analysis has shown that in these years both inter- and intrastate mergers of large banks had a negative effect on branch density at the tract and county levels. The effects of intrastate mergers were especially strong in rural tracts and in tracts in which merging banks had overlapping branch networks.The banks’ efficiency targets changed after the crisis, triggered, in all probability, by the desire to divert more customers to their online services. In recent years, the coronavirus pandemic has served to reinforce this trend. Clients have quickly become accustomed to online banking, and this change in consumer behavior has led banks to reduce their branch operations. One contribution of our paper has been to analyze the way in which banks have adjusted their de-branching strategy in the wake of a merger taking into consideration the level of penetration of broadband Internet and FinTech services. We have shown that, following a merger, banks have closed more branches in tracts with a relatively higher penetration of broadband Internet services; however, we do not find any evidence that mortgage lending by FinTech entities has modified the banks’ branch networks.The main implications of our findings are that public policies promoting bank competition and online banking need to consider their impact on financial exclusion. There is an extensive literature showing that the intensification of competition promotes access to banking services for low-income households, yet market consolidation reduces branch density and can negatively affect the access of the more vulnerable population to financial services. Moreover, branch closures reduce soft information and are associated with an increase in consumer bankruptcy. Improving Internet access in less-dense areas and offering financial advice to vulnerable households seem necessary measures to mitigate the progressive reduction in bank branch networks.