H
ousing costs are emerging as the hidden driver behind America’s falling birth rate.
Benjamin K. Couillard, a doctoral student in economics at the University of Toronto, used U.S. Census Bureau data to trace rent trends across the country. His analysis shows that rising housing prices account for roughly 51 % of the decline in U.S. fertility from the 2000s to the 2010s. If housing costs had stayed flat after 1990, about 13 million more children would have been born by 2020.
Couillard’s model isolates housing from other economic pressures, revealing how affordability shapes both the timing and willingness to have children. He describes it as a “living arrangement model,” where fertility is a key outcome. The study links a 149 % increase in rents between 1990 and 2020—well above inflation—to a drop in the fertility rate from 2.08 children per woman in 1990 to 1.64 in 2020, with last year’s figure hitting a record low of 1.599, far below the 2.1 replacement level needed for a stable population.
Realtor.com senior economist Jake Krimmel, who reviewed the research, praised its precision. “It’s one of those rare findings that’s intuitive, important, and has actionable implications for policy,” he said. “While it’s not surprising that high rents curb fertility, it’s very difficult to prove it in the data. Quantifying the causal link is essential to understand how significant the housing cost channel is relative to other factors like child‑care costs.”
The implications extend beyond the housing market. A shrinking birth cohort threatens the labor force and could strain federal programs such as Medicare and Social Security, which rely on a broad base of younger taxpayers to support retirees. Couillard argues that addressing housing affordability could reverse these demographic trends. “Lower housing costs would improve affordability and help avoid the demographic problems associated with aging populations and declining birth rates,” he noted. He suggests that a “maximalist” housing policy—aggressively expanding supply to keep costs from rising—could solve most of the fertility issue.
Krimmel agrees that the findings highlight a policy gap. “To boost fertility, we need not only more housing but a different kind of housing,” he said. “We must build larger units and apartments that can accommodate growing young families.”
In sum, the study quantifies how soaring rents and home prices have become the primary factor driving the U.S. fertility decline, underscoring the need for housing policies that support family formation and long‑term demographic sustainability.
