Mortality traps and the dynamics of health transitions

Abstract

An examination of life expectancy in 1963 reveals twin peaks in the empirical distribution across countries: one group of countries clustered around a life expectancy of 40 years and a second group clustered around a life expectancy of 65 years. By 2003, the mode of each cluster had moved up by ∼10 years. Although the two groups are similar in that within each of them, there is progress toward higher life expectancy, a number of countries appear to have made the jump from the high-mortality cluster to the low-mortality cluster. We reject the hypothesis that these changes reflect a simple convergence process. The data instead suggest continuous advances among many countries within clusters, with advances in life expectancy in some nations resulting in a jump from one cluster to the other. © 2007 by The National Academy of Sciences of the USA.