Mortality Projections for Japan: A Comparison of Four Methods

Abstract Death-rates at all ages have fallen with an astonishing speed over the past 40 years in Japan. Life expectancy at birth among the Japanese is now the highest in the world for any national population. While most people agree on the advantages of a longer life for the individuals who benefit from it, there is increasing concern, in Japan as elsewhere, about an important side-effect of rapid mortality decline, namely, population ageing. All analysts agree that populations in developed countries like Japan will continue to grow older (whether measured by the median age of the population, the percentage over age 65, or some other indicator), but the extent and speed of this transformation over the next 30-50 years are somewhat less certain and depend, to a large extent, on future trends in death-rates at older ages (Horiuchi, 1991).