The personal saving rate of the elderly is relatively low, so that a rise in the proportion of the elderly in the population will result in a fall in the overall saving rate. Should such a decline in saving reduce capital accumulation, this might also act to depress economic growth.
In fact, the speed at which the population is ageing and the birthrate declining has recently been accelerating rapidly. This trend has not only exacerbated concerns about a possible contraction of the domestic market, but also added to the numbers worried that the pension, medical care insurance, and various other social security systems might be forced toward bankruptcy.