Health Human Capital and Economic Development

Lifespan has doubled in the world in the last 200 years. In the last 50 years, this advance in health, measured by expectation of life at birth, has been shared more equally among people than the increase in income. The record of this concurrent increase in lifespan and income per capita suggests it may be important to understand how these events are interrelated. The connections between health and development are controversial, in part because the evidence on this topic comes from different scientific disciplines, answering different questions, relying on different types of data and using different analytical methods. However, hypotheses are emerging that merit much more study in Africa and elsewhere, to guide the allocation of resources for health, which will entail refinement of conceptual frameworks to isolate causal relationships through more rigorous empirical testing, and collection of new data for more decisive tests. Two types of relationships are distinguished: first, the linkages between conditions under which people live and their expected lifespan and health status, which characterise the technology of ‘health production functions’; second, the relationship between an individual's stock of health and her or his economic productivity, well-being and duration of life, which characterise ‘returns to health human capital’. In the last 50 years, the lifespan at birth of the relatively rich and poor converged, at least until the 1990s. There are indications that this was achieved mainly by improvements in nutrition and control of infectious diseases concentrated in childhood that were relatively cheap to disseminate. To control mortality and reduce disability among adults confronting degenerative chronic diseases has proved more costly, and the relatively poor may thus not benefit as much as the rich from the dissemination of these newer medical technologies unless subsidised. However, the prior reduction in childhood illnesses may itself contribute to improved adult health outcomes later in the life cycle. Birth cohorts which have experienced diminished infections and inflammatory illnesses in utero and early childhood and received better early nutrition may also increase their potential economic productivity as adults, as well as live longer lives free of disability.