As the global fertility crisis continues to accelerate, so does anxiety over what to do about it. A smaller world population may be fine in the short run, but it would not be good for it to asymptotically approach zero, and many citizens presumably do not want their countries to lose their geopolitical influence due to population decline. And in many cases, there is national debt to be paid off, which requires more young people to pay taxes and finance the pensions of the old.

Some countries are taking action. South Korea, which has the world’s lowest total fertility rate — just above 0.7, far below the replacement level of 2.1 — is pondering a radical solution: baby bonuses of 100 million won each, or about $70,000. For perspective, that is about twice South Korea’s annual per-capita income. At current birth rates, the plan would cost more than $16 billion a year; if it is successful, it will cost even more.