I find it ironic that at the same time the world is facing an overpopulation crisis, Japan is facing a crisis of underpopulation. Last year I spent 3 months in Japan, and heard the subject come up at least 10 times, in casual conversation, on tv shows devoted to discussing the crisis, and in a fifth-grade social studies class. Almost everyone in the country seems to be able to cite the low birthrate statistics: 1.3 nationwide and a mere 0.9 in Tokyo.
I saw the current effects in the shrinking schools I visited. My wife's elementary school has half the students it did when she attended. Others already affected include seniors, who are increasingly living alone in a culture that still assumes the norm to be children living with their aging parents. Also,
As for solutions? Allowing mass immigration is one possibility. Robots