Vast improvements in human health have been made during the past century. Indeed, gains in increased life expectancy and reduced physical impediments for much of the population were greater than in any previous century. Yet the gains were not uniform across the world or even within individual countries. The variations in health status among people cannot for the most part be explained through genetic differences. Instead, in most instances the variations in the last century and at the turn of the current century correspond to the variations in the distribution of control over material resources.
