By the end of the century, under the assumption of constant fertility, the economically active population (aged 15 to 59 years) of Western Europe will fall by two-fifths, and of Eastern Europe and East Asia by about two-thirds. The working-age population of the United States will grow by about a quarter. The least fertile European countries will see their total populations drop by 40 to 60 percent in the course of the present century.
My bet is that this is optimistic, but immigration will take off.
