"There has been so much Schadenfreude about Japan's two "lost decades" over the past few years that I have often taken the contrary view by pointing out that actually Japan's growth adjusted for inflation and population growth over the past twenty years has been about the same as that of the U.S. while its productivity growth has been higher. Still, there is that population element. The Japanese people are aging rapidly and are fewer every year. It is very hard to build an economic success story on that kind of a foundation. And that holds for Germany, Italy, South Korea, Taiwan, Singapore, and China."
More: Things could be worse, America | Prestowitz
I do know that Japan suffers from depopulation since the national birthrate is declining. To my best knowledge, Japan doesn’t have one-child policy. However, does the underlined part mean that majority of Japanese people are elderly, generally speaking?
It means that the average or median age of the Japanese population is rising rapidly.