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Underlying the health improvements that countries achieved were investments informed by advances in public health science. Periodic epidemics of cholera, malaria, and other infectious diseases plagued Europe and the Americas during the nineteenth century until the science of disease transmission developed and viable interventions were discovered. Major investments in public health in the nineteenth century—in response to the work of Snow (1849) linking contaminated water with cholera—resulted in dramatic declines in mortality. Simply eliminating people’s contact with sewage-contaminated water contained the cholera epidemic in London in 1854 (Crossier 2007). Similarly, the Thames embankment, which helped the river to move effluent out of London, and the draining of swamps elsewhere led to the disappearance of malaria in the United Kingdom (Kuhn and others 2003). More recently, Cutler and Miller (2005) have studied the impact of clean water on health, looking at the results of the adoption of filtration and chlorination by U.S. cities in the first quarter of the twentieth century. They attribute nearly half of the total reduction in mortality in major cities, three-quarters of the reduction in infant mortality, and two-thirds of the reduction in child mortality to improved water supply.

An important factor that facilitated the introduction of public health measures was centralized decision making with little involvement of citizens, driven by economic imperatives. Eminent domain effectively ensured that public health measures in Europe and parts of the Americas were implemented before the twentieth century. Beginning in the mid-nineteenth century in the Americas, concerns about contagious tropical illness such as yellow fever, cholera, and malaria prompted the region’s governments to adopt the Pan American Sanitary Code, which entailed the adoption of intense disease surveillance and reporting, control of disease vectors, sanitary improvements, and significant investments in parasitology research centers across Latin America to limit quarantine-related and other delays to regional trade (PAHO 1999). A recent example of collective action to enhance human and economic well-being is the multicountry- and multidonor-funded Onchocerciasis (river blindness) Control Program in the Niger delta in West Africa. The program of spraying infected areas with pesticide has effectively controlled the black flies responsible for this debilitating and lethal human infection. It has enabled the recultivation of 25 million hectares of fertile agricultural land, which had been abandoned because of the prevalence of the disease (Benton 2001).

Other such public health interventions are needed across the developing world to deal with some of the same challenges that confronted European cities in earlier times. The World Bank estimates that a billion people lack access to clean water and 2.6 billion (or roughly 40 percent of the world’s population) lack access to basic sanitation. Some 94 percent of diarrheal cases worldwide can be attributed to unsafe drinking water, poor sanitation, and inadequate hygiene, with 1.5 million cases resulting in death, mostly among children (World Bank 2008). The importance of these basic public health measures to promoting good health and reducing mortality remains fundamental to investments that have demonstrated links to expanding economic activity.

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