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Low birthrates have turned Japan into a “demographic time bomb.” South Korea is facing an existential crisis in aging, and Europe, as the Guardian warned last year, “needs many more babies to avert a population disaster.”

Then there’s the U.S.: While the country is indeed getting older and Americans are making fewer humans on average, the birth decline has been offset — at least in part — by the fertility rate of migrant mothers, as Ben Casselman notes at FiveThirtyEight. Indeed, in a recent blog post, Pew senior researcher Gretchen M. Livingston reports that foreign-born mothers “are responsible for the nation’s long-term growth in annual births.” The total number was 3.74 million babies in 1970, and it went up to 4 million in 2014.

As the native-born birthrate goes down, the foreign-born goes up. “In 2014, immigrant women accounted for about 901,000 U.S. births, which marked a threefold increase from 1970 when immigrant women accounted for about 274,000 births,” Livingston writes. “Meanwhile, the annual number of births to U.S.-born women dropped by 11% during that same time period, from 3.46 million in 1970 to 3.10 million in 2014.”

To this day, immigrants have a disproportionately high birthrate, she adds: While 14 percent of the U.S. population was foreign-born in 2014, 23 percent of newborns that year had foreign-born mothers.

The growth in annual U.S. births since 1970 has been driven entirely by immigrant moms https://t.co/hJPxlyZydn pic.twitter.com/q3I0P8hS7x — Pew Research Center (@pewresearch) November 3, 2016

If it weren’t for people moving to America, the birthrate would have slid, and America would have gotten — and would be getting — older, faster. Aging populations present big risks for a country’s economic well-being, since it means a lesser portion of the population will be of working age, and a greater portion will be dependents — the very young and the very old. Economists call it the “dependency ratio,” and the Pew data suggests that in the U.S., immigrant births are helping to keep it from getting out of control.



The stabilizing quality of immigration is something that gets left out in a time of nativist campaign rhetoric. To have a fair and balanced conversation about immigration, it’s important to note that, yes, immigrants aged 25 and older are three times more likely to not have a high-school diploma, putting them in competition for low-wage jobs, but immigrant children far outpace other kids from kindergarten through high school, at least according to one representative sample. Also, immigrants commit far fewer crimes than native-born Americans, and urbanists argue that because of the way they spur development, pro-immigration policy — like in New York and Washington, D.C. — is one of best ways, over the long term, to change the neighborhood contexts that produce crime.