The USA is the standout among industrialized populations. In the 1970s, our birthrate had drifted down to 1.7 kids per woman, as had happened in Europe. Europe kept going down, to the scary lows of 1.3 today. We, on the other hand, went back up. Currently the Total Fertility Rate of the United States is about 2.06 -- not quite replacement, but close.
In addition to having a respectable fertility rate, we do immigration right, as Ben Wattenberg writes in Fewer. We admit about 750,000 legal immigrants per year, and another quarter or half a million illegals. The illegal immigration is not, of course, "doing it right." Fixing that is a problem for another post. But the total number of immigrants we admit -- about a million a year, on a base of 300 million -- is a good number.
Alarmists claim we are being swamped by immigrants, but really we are absorbing the new Americans pretty well. Immigrants and their children make up a fifth of Americans today. In the 1920s, though, first and second generation immigrants made up a third of the U.S. population.
Immigrants have more kids than native-born Americans. Since our current TFR is a little low, this is a good thing. Yet the immigrants are not likely to bury the native-born demographically. Fertility rates fall to the national norm by the third generation. English speaking rises to national norms by the third generation. And intermarriage rates rise about 50% by the third generation for immigrants from Asia and Latin America.
The United States, alone among developed nations, is holding its population steady. It did so when world population was rising alarmingly, and is likely to do so now that world population may start to fall alarmingly.