Healthy Life Expectancy in Japan, Taiwan, and the United States

Japan’s extraordinary low level of old-age mortality is well documented compared to other countries. Less well understood is how the health of the Japanese older population fares relative to other countries, and whether differences persist in consistent ways across major domains of morbidity – chronic diseases, functioning and disability. To the extent that Japan’s low mortality is brought about by the postponement of disease and its sequelae, we would expect to see cross-national differences in the timing of morbidity across all major domains. Here, we compare Japanese mortality and morbidity to the mortality and morbidity experiences of older populations in Taiwan and the US. We draw on demographic models of healthy life expectancy to summarize how major domains of morbidity combine with all-cause mortality to produce cross-national differences in the years of life with and without major types of morbidity. We use a simulation approach to evaluate how morbidity/mortality timing shapes the cross-national differences in healthy life expectancy. By using Japan as a standard, this study will provide unique insights into the possible morbidity avenues by which a population’s health can be significantly improved.