D. Elderly/children Ratio
As mentioned avove, one interesting indicator for showing the change in age-structure is the elderly/children ratio, which is the number of the elderly (population aged 65 and over) divided by the number of children (population under 15), multiplied by 100. In 1930-1950 the ratio was as low as 13, that is to say, there were relatively few elderly persons in proportion to children. However, the elderly/children ratio has been increasing, and by 1986 it reached approximately 50 per 100 children. In 1997, it has already reached the mark level of 100 (see also Figure 5). According to the projections prepared recently by the National Institute of Population and Social Security Research 1997, the ratio will increase further. Astonishing as it may seem, by the year 2050 it will soar to 247, that is to say, the population of the elderly will be nearly two and a half times as much as that of children.
There are few countries whose elderly/children ratio is more than 100 at the present time. Sweden, the Federal Republic of Germany (before the unification) and a few others show elderly/children ratios being close to 100 in 1995. Around 1986, when the elderly/children ratio was only 50, the Japanese started a kind of over-reacting to the rapidity of population ageing, as if their population has already turned grey. Hence, it is difficult to imagine how people would react to the situation where the population ageing is really in full swing. Japan is now entering an entirely new phase of demographic evolution, in which the elderly will outnumber children.
E. Rapidity of Population Ageing
As already mentioned, in Japan the term "population ageing" is not shibboleth but a household word, and there have been so much debates and speculations which have been going on. Why so? Some reasons may be attributable to the high educational standard in which Japanese people might exhibit their concerted interest in social changes, but it seems largely attributable to substantial seasons. That is the rapidity and swiftness of population ageing in Japan.
According to Tables 1 and2 as well as in Figures 5 and 6, the trends have already been clear. Before 1985 or so, though the issues of population ageing had already been debated hotly, the actual proceeding of population ageing was rather slow and the percentage of the population 65 years and over is hardly beyond 10 percent. However, after 1985, the momentum has been gathering and according to the population projections shown in Table 2 and Figure 5, the population ageing is expected to proceed at an unprecedented speed and by the year 2025 the percentage of the aged is projected to be more than 27 percent.
