Ever since Scott Halstead and colleagues published Good Health at Low Cost (Rockefeller Foundation, 1985), we have known that some countries reduced child mortality and extended life expectancy dramatically without first becoming rich. The required means did not seem mysterious, either: concentrate on a small number of highly cost-effective interventions, notably immunizations and oral rehydration, against the major childhood killers, while avoiding more expensive medical technologies. Sri Lanka and Kerala state in India stood out as poor but healthy successes, but ones that seemed to depend on particular social conditions, especially a high level of female schooling and autonomy of action. Cuba, another health success, depended on relatively massive investments in health personnel and facilities and is therefore also a model difficult to copy. The question of whether economic development is essential to improvements in health therefore remained somewhat open for other countries.
More recent research has gone in two directions. One is to examine successful control of individual diseases or conditions. Ruth Levine and colleagues, Millions Saved: Proven Success in Global Health (Center for Global Development, 2004), examined seventeen cases, including smallpox, polio, trachoma, and diarrheal disease, looking for the factors that made large-scale control possible. High income was never one of the causes. The other direction takes infant mortality as the marker of health status and asks why that improved at very different rates in different counties over the period 1962–87. Differences in the uptake of technological progress appear to account for two-thirds of the health improvement; income growth explains only 7 percent. 1
Both of these approaches are welcome for getting away from simple cross-sectional comparisons, where income and health status are strongly associated, and looking into the history of health gains. James Riley, a professor of history at Indiana University, has pushed the history back farther, into the late eighteenth or early nineteenth century for the “pioneers” of transition in life expectancy and into the mid-nineteenth to the first half of the twentieth century for countries undergoing this transition later.
This approach has three advantages to compensate for the difficulties of accurately measuring either income or life expectancy 100 or 200 years ago. First, it emphasizes the period before antibiotics and most vaccines were discovered, so the meaning of technical progress and the health interventions that embodied it are different from what those terms mean from about 1950 onward. Hand washing, pit latrines, quarantine, quinine plus drainage and larviciding against malaria, and measures to reduce tuberculosis infection were, along with smallpox vaccination, what mattered most. All of these measures but the last are still valuable and require widespread adoption to improve health, but they have been partly superseded by curative interventions with a higher degree of medicalization.
Second, Riley applies Walt Rostow’s “take-off” metaphor to sustained increases in life expectancy and compares their timing to the takeoff in income growth. This turns up an interesting contrast. The pioneer countries, mostly Western European, “took off” in economic growth some decades before they began to achieve much longer lives for their citizens. The twelve countries he studies that began a health takeoff somewhat later did so while remaining relatively poor, or before achieving major income growth. So it appears that economic development might have been essential for health improvement up to roughly the mid-nineteenth century but not afterward, so long as a country could reach a threshold level of around $1,000 per capita (in 1990 international dollars). The change from income-first to health-first depends greatly on progress in understanding the causes of disease and how to control them, an understanding that advanced significantly even before the discoveries of the modern era.
Third, by looking farther into the past, Riley can consider a variety of countries (Mexico, Japan, Russia, Cost Rica, Cuba, Korea, Panama, China, Jamaica, Sri Lanka, Venezuela, and Oman) that differ much more in income and other characteristics today than they did when their health transitions began.
This thorough study appears to drive the final nail into the coffin of the idea that economic development (beyond a modest threshold) is essential to improved health. In fact, living longer in reasonable health seems easier to achieve than living materially richer, besides being intrinsically more valuable. What does it take for that to happen? Riley’s answer is “social growth,” as distinct from income growth. This rather elastic term includes some of the features emphasized in other research, particularly schooling, and for girls as well as boys. But it means something more, something harder to define: a population’s willingness to understand and adopt the relatively simple measures that increased life expectancy, mostly by preventing disease, before the era of antibiotics. Formal schooling matters less than specific, widespread understanding of diseases and their causes. Governments suddenly made rich by oil (Venezuela and Oman) can speed the health transition dramatically. Most of what needs doing, however, costs little and can be furthered by regimes of very different political orientation and degree of dictatorial control.
Riley’s discussion of what social growth is and how it works is sketchier and less satisfactory than his analysis of income and life expectancy. Few data exist on such specifics as population coverage with latrines or the actual behavior that reduced tuberculosis transmission. Sometimes the explanations even seem rather naïve. No matter: sticking primarily to the economic and demographic story goes a long way toward settling the question of their relation and how it has changed through time—and it keeps the book conveniently short while pointing the reader to many other sources and suggestive pieces of research.
Philip Musgrove ( [email protected] ) is a deputy editor of Health Affairs . Before joining the journal’s staff, he worked for three years as an editor of the Disease Control Priorities Project at the National Institutes of Health, and for twelve years before that as an economist specializing in health at the World Bank.
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D.T. Jamison