By 2100, the population of the world’s poorest countries will more than triple, from 954 million in 2015 to 3.2 billion.

Minus immigration, the populations of the U.S., Japan and all of Europe are shrinking. By 2050, 48 countries or areas will have fewer people. Several will see a 15% decline, including Japan, the Balkans and the Baltics, and some much more.

In 2016, the fertility rate in the United States was the lowest it has ever been, according to the Centers for Disease Control. It was 1,765 births per 1,000 population, below the replacement rate of 2,100.