Worldwide people’s health has vastly improved in the last two hundred years, yet there remain vast inequalities between countries. For instance, child mortality rates are 14 times higher (74 deaths per 1000 live births) in low-income countries compared to rich countries (see here). Similarly, large health differences among individuals persist within nations, regardless of their level of development. In the United States, the adult life expectancy gap between the richest and poorest was about 15 years during the period 2001-2014 (see here). In England, people living in the most deprived areas live between eight and nine years less than residents of better-off communities (see here). These between- and within-country health gaps are incredibly persistent (see here or here), which begs the question: What can we do to close them? To answer this, we first need to understand when, how and why health progress started and how it spread (unequally). This is the aim of our research portal, Long-Run Health Matters (LRHM), which began one year ago.
So far LRHM has published a number of research summaries on long-run health by leading experts in various fields, including history, economics, economic history, demography or epidemiology. This post puts together these contributions in an accessible and concise manner. I will divide the contributions along three broad themes: (1) health, institutions and development; (2) epidemics, inequality and climate; and (3) the societal consequences of health.
1) Health, institutions and development
Over the past two centuries most parts of the world achieved substantial health improvements. people live much healthier lives. A health transition characterized by the decline of infectious illnesses and infant mortality as well as the rise of chronic diseases has shaped the mortality patterns we observe today (excluding recent developments due to COVID-19). Janssens (see here) presents a new approach to understand this transition by focusing on individual-level information about cause of death, place of residence and other aspects of individuals’ lives, such as sex, marital status or gender. Using the case of Amsterdam during the period 1856-1926, she shows that an important share of deaths were attributed to vague diagnoses, such as ‘weakness’ or ‘convulsions’, and that they gradually disappeared by the 1920s when diagnostic capactity improved. An important finding from her research is that from about 1910 onwards water- and food-borne diseases largely disappeared, due to improved hygiene and piped water (among other factors).
The idea that access to sanitation is an important factor explaining why some places are healthier than others is explored in detail by Jaramillo and colleagues (see here). They construct a new dataset on mortality rates and the provision of clean water and sewerage services in Colombia during the 20th century. Their analyses indicate that places with these sanitary infrastructures in place experienced greater mortality declines, mainly due to the reduction of gastrointestinal and waterborne illnesses. Indeed, waterworks and proper waste disposal reduce human contact with contaminated water and feces, and thus avoid a substantial amount of easily preventable suffering (particularly by children). For a more recent period (2009-2012), Frempong and Stadelmann (see here) find evidence that closeness to improved water installations in Uganda was associated with a higher chance of using improved water. Also, women and children travel shorter distances to collect water after the completion of such projects. Interestingly, though, they fail to find a robust relationship between access to clean water and the incidence of diarrhea, unlike the earlier piece on Colombia.
If the link between the provision of sanitary services and public health is not straightforward, the same applies to how industrialization and development affect health outcomes. A common narrative argues that British industrialization was detrimental to the health of contemporaries, especially for those living in urban areas. Davenport (see here), however, argues that urban life expectancies did not experience a significant decline when urban growth was most rapid in the 1830s and 1840s. Although there was a slight increase in mortality, this was not limited to urban areas as rural communities also experienced rising death rates, possibly due to the increasing virulence of scarlet fever among young children throughout the country. One might argue that focusing on health outcomes exclusively would be insufficient to assess how industrialization transformed British society and people’s lives. Gallardo-Albarrán and de Jong (see here) look at the early phase of British industrialization and construct a novel index that aggregates four crucial dimensions of human welfare (income, health, working time and inequality). They find that human welfare in England evolved very differently before and after 1800. Between 1760 and 1800, they observe a process of worsening human welfare as a result of declining material living standards, rising working time and surging inequality. After 1800, though, the situation dramatically improved. Working time and inequality stopped rising and wages experience a positive trend, despite health stagnating during the first half of the 19th century. The piece concludes that to understand the manifold consequences of industrialization we need a framework that goes beyond measures of material living standards and puts all relevant aspects of human welfare together.
Did the human welfare accumulated by expanding purchasing power and better health during industrialization also lead to a happier society? Lack (see here) answers this question by examining the trend of emotional well-being during the 19th century in Britain. He measures this somewhat elusive concept by calculating the frequency of happiness-indicating relative to sadness-indicating words from a corpus of pamphlets published between 1800 and 1900. He finds that despite rising income per capita, emotional well-being remained stagnant during the analyzed period. This might be explained by changes in inequality or declining social capital. Alternatively, the results of this research might be explained by the relative income hypothesis, which holds that satisfaction depends on a national or international reference point that changes as income changes and people adapt to the new circumstances. In any case, it seems that more money, consumption and material amenities did not necessarily make people happier in the 19th century, an idea that speaks to current trends of social and political discontent despite living in the richest era of the human species.
Although higher purchasing power might not make people happier, higher income does have a direct impact on individuals’ consumption patterns and nutrition. In turn, this can influence their health. Schneider’s post (see here) considers children’s health and nutritional status in the London Foundling Hospital at the turn of the 20th century. With detailed data on heights and weights as well as sickness duration by five diseases – measles, mumps, rubella, chicken pox and whooping cough), he finds that malnutrition did not affect the propensity of children to contract these ailments. The reason is that the illnesses were so infectious that children would have caught them whether they were malnourished or not. However, his study does find that children with worse nutrition experienced longer periods of sickness due to measles and mumps. Also, malnourishment led to complications from measles. In sum, nutrition was, and still is, an important reason why some children suffer much more from infectious diseases than others.
While public health infrastructures, vaccination campaigns and other large-scale interventions influenced health outcomes, so did working conditions and the institutional framework in which these were created. De Zwart and colleagues (see here) argue that colonial institutions shaped the demographics of java by studying how the Cultivation System– a Dutch colonial system of forced labor operating during the 19th century – impacted the health of the population. Their findings show that forced labor demands led to higher mortality rates. As most labor in the colonial system was performed in unhygienic plantations, these formed hotbeds of infectious diseases that then spread when workers moved and interacted with their peers in the region. They argue that the effects of colonial policies on development trajectories were manifold and that we need to expand our approaches beyond economic ones to comprehend colonial legacies fully. Taking a longer perspective, Bolt and colleagues (see here) consider the colonial past of Africa to examine the historical roots of institutionalized health care in the region. They find that places with medical infrastructures during the interwar period have more public health care facilities nowadays in Cameroon. This relationship is influenced by the provider of these services (government or missions), as regions with more government investment in the past exhibit more hospitals at present. In addition, they argue that past health care resulted in a more favorable attitude towards Western medicine, stronger political voice and higher human capital.
A clear message from the two posts above is that health infrastructures, and their institutional embedding, matter for long-run health, which leads to the question: which factors lead to the implementation of these costly infrastructures? Pons-Pons and Vilar-Rodríguez (see here) tackle this question by tracing the roots of the Spanish hospital system during the dictatorship of Francisco Franco. Their research highlights the importance of the cooperation between the public and private sectors, since the construction of large public hospitals was much slower than envisaged during the early years of the dictatorship, and private actors complemented public efforts. However, by the end of the dictatorship universal coverage was not achieved, among other factors, due to the shadow of corruption among decision makers over the management of the health care system, the lack of coordination of public hospitals and the failure of legal changes implemented in the 1960s to have a tangible impact on the hospital system.
The evolution of our health care sector depends not only on political factors, but also on demographic and economic ones. Rodríguez-Sánchez (see here) examines the relevance of these factors by considering the functioning of another pillar of our system of care service provision during recent times: nursing homes. She argues that diabetes is an important driver of why the elderly are brought to nursing homes, since functional complications due to this disease increase the vulnerability and dependence of citizens, especially among the oldest. The construction of a fair and more efficient health care sector, she concludes, is crucial given current trends of population aging and associated costs.
Institutional settings coevolve with cultural norms and beliefs, sometimes formalizing ways of discriminating against some people, such gender discrimination, deeply influencing the health of females. Beltrán (see here) studies whether girls in historical European populations were ‘missing’, as a result of sex-selective abortion, female infanticide or the mortal neglect of young girls. He looks at the regularity (or lack thereof) of sex ratios and finds that this phenomenon was widely prevalent in many regions, especially in southern Europe. Many communities exhibited son preference as the perceived value of girls was lower, especially in strong patriarchal cultures based on patri-lineal kinship and dowry systems.
2) Epidemics, inequality and climate
Are epidemics ‘leveler’ events that tend to reduce economic and social inequality? Or do they magnify existing gaps among individuals? Two of our posts support the former idea. First, Fourie and Jayes (see here) consider the case of South Africa and examines whether access to health care became more unequal during the 1918 Influenza. With information from individual-level death certificates, they examine whether they were signed by a health official or not, as an indicator of whether that person had access to medical services. They find significant differences in health care access among ‘black’, ‘coloured’ and ‘white’ individuals at the turn of the 20th century, and that these differences were exacerbated during the epidemic. Likely explanations include differences in income and residence. The second post by Rosés and colleagues (see here) study the economic impact of the 1918 Influenza on the Spanish economy. They find that most economic activity declined in the service and manufacturing sectors, but not in agriculture. In fact, harvests were not interrupted during the pandemic! The fall in economic output was short lived and driven by demand forces, as mortality was higher in poor and agrarian regions and real wages decreased more in urbanized and industrialized ones. Also, as capital returns were unaffected, or positively affected in the case of house prices, economic inequality increased.
How are epidemics related to weather changes? Tumbe (see here) looks at three major disease outbreaks in India – cholera, plague and influenza – arguing that ‘seasonality’ was an essential element in how those diseases spread and were understood by contemporaries. Beginning with cholera, colonial officials refused to accept the theory that it was transmitted through contaminated water because it had a distinctly seasonal pattern, and thus was associated with environmental factors. It took decades until the germ theory of disease was widely accepted and proper sanitation began to be implemented until the disease started receding. Tumbe estimates that 20 million people died due to influenza between 1918 and 1920. Death rates were particularly high in northern India, which suffered the third worst drought in India’s recorded history. Consequently, food shortages and grain inflation led to malnourishment, weaker immune systems and worse mortality rates than in other Indian regions.
Plague and smallpox have taken countless lives throughout history, but only the latter has been eradicated. Why? Schmid (see here) highlights how modern medicine (e.g. vaccination) is often hailed as critical in the eradication of smallpox, while the same does not apply to plague. Indeed, the latter is still present among wildlife rodents worldwide and often leads to sporadic infection in humans. In any case, one aspect of our fight against plague that can be widely celebrated concerns its mortality rates during the last two centuries, which have greatly declined. Many factors can account for this development. For instance, we currently live in buildings with better quality, far from unwelcome rodents or livestock. Also, higher temperatures and lower humidity at home reduce the number of fleas living with us.
3) Societal consequences of health
One group of articles published at LRHM considers the consequences of health on political developments and the evolution of well-being. Concerning the former, Galofré-Vilà and colleagues (see here) study whether changes in mortality rates can account for one of the most important political events of the 20th century: the rise of the Nazi party in Germany. They use data on voting data during four national elections between 1930 and 1933 and link them with cause-specific death rates. They find a robust relationship between the health of the population and Nazi party vote share, even after considering the influence of potential confounding factors such as income. Their research suggests that epidemiological data can be employed as a ‘canary in the coal mine’ to identify when lack of social progress may increase the susceptibility of the population to populist messages.
Another consequence of health changes concerns the well-being of the population. But, how can such a broad and multi-dimensional concept be measured? Harris (see here) argues that average heights reflect average changes in biological well-being, since these depend on economic factors (e.g. disposable income), societal arrangements (e.g. distribution of resources within a family or a population) and environmental influences (e.g. burden of disease). He shows that Europeans have grown much taller since 1750 and that these trends, as well as the underlying forces driving them, are essential to understand human biology and how this may influence (or be influenced by) broader economic and social processes. Prados de la Escosura (see here) also considers that health is a critical input for overall well-being in the 20th century. He takes a different approach in measuring how the former contributes to the latter by constructing an index that aggregates income, health and education, akin to the well-known UN Human Development Index, and assumes that gains in these dimensions (except for income) at high levels represent more substantial achievements than at low levels. For instance, expanding life expectancy beyond the age of 80 when many die because of cancer or cardiovascular conditions is much harder than at age 30 when people suffer from treatable infectious diseases. Using this index, he finds that health developments have been a significant engine of human flourishing during most of the 20th century. Global health improved post-World War II when new drugs (e.g. antibiotics) from high-income countries diffused worldwide and massively reduced the burden of mortality. Since 1970, poorer countries have not experienced a second health transition, thus weakening the contribution of life expectancy to improving human development. The long-run perspective offered by Prados de la Escosura suggests that while inequalities remain, there is substantial potential for improving the lives of millions and making the world a more equal place in which everyone can lead healthier lives.
The road ahead
The articles covered in this posts represent only a small fraction of the knowledge frontier on long-run health issues. In the coming year, LRHM will continue scouting different academic fields to bring you what I think are relevant pieces of research to understand one of the major topics of our time: the sources of health progress and inequality. I hope you remain with us in this exciting endeavour!
Assistant Professor (Wageningen University)
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