A new study suggests that the birth rate is collapsing in the San Francisco Bay Area, partly due to high housing prices, as women are delaying childbirth until they can afford living space in which to raise children.

San Francisco has never been known for having large numbers of children (“flower children” aside). As Breitbart News noted in early 2017, the city of San Francisco “has the lowest percentage of children of any major city in America.”

That is partly due to the area’s relatively high proportion of gay and lesbian couples. But it is also due to economic factors, such as the high cost of living, and institutional factors, such as the lack of high-quality public schools and child-friendly parks.

Another factor, according to real estate site Zillow, is the high price of housing. The East Bay Times reports:

A new study by real estate website Zillow suggests many Bay Area women may be putting motherhood on hold at least partly because of the region’s housing market. The fertility rate is dropping across the country for women between the ages of 25 and 29, but the dip is most pronounced in counties where home prices are rising rapidly — including Santa Clara, Alameda and San Francisco.

Nationally, on average, every 10 percentage point increase in home values was associated with a 1.5 percentage point drop in birth rates for women ages 25 to 29, according to the study, which chose that group as the age when women are most likely to be considering having children but do not yet own their own home.

But the drop in births was even more pronounced in the Bay Area. In Santa Clara County, home values rose 58 percent between 2010 and 2016, while the fertility rate of women ages 25 to 29 dropped 20 percent. In Alameda County, home values rose 60 percent while the fertility rate dropped 24 percent. And in San Francisco, home values rose 61 percent while the fertility rate dropped 22 percent.

The Zillow study itself, “Birth Rates Dropped Most in Counties Where Home Values Grew Most,” warns that the birth rate is not recovering as the economy recovers, despite Americans’ expressed preference to have more children.

Texas and the southwestern U.S. were exceptions: there, birth rates rose faster than the rise in home values would predict, according to Zillow’s model.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named to Forward’s 50 “most influential” Jews in 2017. He is the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.