International economic inequality as predictor of global health, life expectancy, and the burden of illness

The first quantitative models of global life expectancy and the burden of illness are now available for the explanation of health trends throughout the world. We can identify the key predictors of global health which include the world economy, environmental and behavioral risks, health care technology, and international epidemics. The challenge is to bring these data together in a manner that will clarify the highest priorities that international bodies, government, and non-governmental organizations can pursue as a means of improving health.

The new world model is constructed and tested on integrated data for 140 countries from the World Health Organization, the World Bank, the International Labor Organization, and the Food and Agricultural Organization. These quantitative models can now account for 87-90 percent of variation in life expectancy. Multiple regression analysis shows that for many countries poverty is still a key issue in developing and even industrialized societies. This is compounded by the current food, energy, and credit crises, by international recession—and continued rapid population growth as well as the HIV epidemic in Africa.

However, GDP (i.e. income) growth itself is statistically not as important as overall economic development which involves substantially reducing the proportion of the economy that is based on agriculture, and expanding that which is devoted to services. This requires investment in the diffusion of science and technology and in primary and secondary education. Population growth, pure water/sanitation and nutrition nevertheless remain the most important predictors of life expectancy across world societies—even in the 21st century.