With a median age of 48, Japan is the oldest country in the world. In fact, a quarter of its population (28%) is 65 years old or older, a proportion that’s expected to rise to 38% by 2050. Diminishing birth rates coupled with increased life expectancy in recent decades lie at the root of this demographic trend. In fact, by 2050, the number of working people is expected to equal that of retired people! Interestingly, while marriage is still strongly valued in Japanese culture, marriages there continue to decrease. Furthermore, only 2% of births take place outside of marriage, and about a quarter of Japanese people don’t marry by the time they reach age 50, another explanation for the decline in birth rates.
The problem, as you probably figured out, is not having enough wage earners paying into the “system” to support the retirees and social programs. Add in the fact that Japan consists of a single race, and a single culture, limiting immigration and expats. That means either zero or negative population growth.

Japan needs 2.1 births to replace the population. The current birth rate is only 1.4, one of the lowest in the world. Their baby boomers are living much longer. Many female boomers chose not to have children, or to marry at all. Women who marry are marrying at an older age, having to choose between a career and a family.
From the AP:
The total of 599,636 Japanese born in January-September was 4.9% below last year’s figure, suggesting the number of births in all of 2022 might fall below last year’s record low of 811,000 babies, he said.
Japan is the world’s third biggest economy but living costs are high and wage increases have been slow. The conservative government has lagged on making society more inclusive for children, women and minorities.
The number of births has been falling since 1973, when it peaked at about 2.1 million. It’s projected to fall to 740,000 in 2040.

Japan’s population of more than 125 million has been declining for 14 years and is projected to fall to 86.7 million by 2060. A shrinking and aging population has huge implications for the economy and for national security as the country fortifies its military to counter China’s increasingly assertive territorial ambitions.
Most of Europe is also experiencing lower birth rates. France is the only country to recover from lower birth rates. The government in Japan under Prime Minister Abe took steps to make it easier to raise children with free education, expanded nursery care, and paternity leave for fathers.
And it is certainly easy to see how and why immigration helps the economies of certain countries, like the U.S.
Stay tuned in the coming decades for big changes, good and bad.