Visual Explanations for Diverging Mortality Trends in High-Income Countries

Life expectancy is increasing in most high-income countries. The development is not uniform, though. Whereas some countries experienced steady progress during recent decades, others have periods of stagnation and, eventually, phases of catching up.

The aim of our paper is to investigate whether comparable developments
in life expectancy are based on the same underlying mortality dynamics. We use surfaces of rates of mortality improvement as our tool of analysis. Based on two-dimensional plots of smoothed death rates, our ``maps'' depict the rate of mortality change over time. We argue that this approach provides an excellent exploratory tool to visually analyze mortality dynamics, in particular to detect age-, period-, and cohort-effects. Preliminary results demonstrate for international comparisons that periods of stagnation followed by rapid increases can be caused by cohort factors (e.g. Denmark) as well as by period factors (e.g. East Germany).

An analysis by major causes of death for the United States shows that
antagonistic cohort effects were instrumental for the slow life
expectancy increase during the 1980s and the 1990s: If negative cohort
effects of respiratory diseases and cancer had been absent, life
expectancy would have increased much faster due to improvements in
survival for heart diseases.