When you look at the numbers by race, you see yet another component of our fertility dynamics. Among non-Hispanic white women, the fertility rate remained roughly unchanged last year. The big drop came among Hispanic women. This development is probably the result of two phenomena: (1) The Great Recession put the brakes on illegal immigration from Mexico and South America. Over the last two decades, there immigrants have accounted for a disproportionate share of American fertility, so any decline in immigration is going to result in a decline in our overall fertility numbers. (2) One of the remarkable aspects of non-native Hispanic fertility is that our Hispanic immigrants arrive with very high fertility rates—but they regress to the native average very quickly.

So in that sense, the decline of our Hispanic fertility rate that we see in the new data is probably the beginning of a larger trend which we’ll continue to see as immigration continues to slow and the Hispanic immigrants who remain in America continue to move toward the mean.

Finally, buried deep in the report is the most telling number of all: In the last year the number of “first” births dropped to the lowest level ever recorded in America. What does that mean? It means that we’re slowly bifurcating into a country where there are two kinds of adults: people who have children, and people who do not. The people who have children are inclined to have seconds and thirds. But for the first time in our nation’s history, we’re growing a sizable cohort of adults who remain childless their entire lives.