1. Demography and Population Ageing in Japan
A. Change in Age Profile
In discussing the general trend in population ageing, it is useful to compare various age profiles, or what has conventionally been called "population pyramid" , in different years which are indicative of demographic transition at different stages that Japan has undergone. "Demographic transition" is here taken to mean a process of demographic transformation from high birth and death rate to low birth and death rate along with the course of modernization and economic and social development.
Figures 1 and 2 show age profiles of the population of Japan in 1950 and 1995. Figures 3 and 4 show age profiles for the years 2025 and 2050. The age profiles for 1950 and 1995 represent the actual ones, but the other two are projected ones based on the latest population projections prepared by the National Institute of Population and Social Security Research (1997).
These four age profiles depict dramatic changes occurred or occurring according to different demographic regimes over a long span of time covering 100 years, and the general reader will get from these graphs some ideas about population ageing that has been going on along with the demographic transition.
The first one for 1950 in Figure 1 looks really like a "pyramid" . Although the shape is of ruggedness with minor dents and bumps, particularly troughs at ages 4 and 5, the general contour is unmistakably bottom-heavy, triangle-shaped and is somewhat typical of present-day developing countries.
On the other hand, Figure 2 shows the profile for the year 1995 dramatically divergent from the above-mentioned profile for 1950. It looks actually a quite complex shape resembling a Japanese war helmet (kabuto) and clearly tracing the vestige of World War II. Yet, there are one or two clear traits which are characterized by its shrinking lower (younger) sector of the population and by a very large body of middle and early-elderly age groups. This population pyramid may be said to be the one starting to experience a considerable degree of population ageing.
