Suburbia and mortgages drive fertility. By Daniel Hess at More Births.
Starting in 1925, long before modern birth control and the sexual revolution, fertility fell below replacement in more than a dozen developed countries and stayed below replacement for more than 15 years. Then as now, housing was a big cause of birthrate decline. …
Fertility in the 1930s was below replacement across virtually the whole of Europe. … Then, as now, the low birthrate crisis was most acute in cities, which were seen as inhospitable to children. In fact, in the crowded European capital of Vienna, fertility fell to one quarter of replacement, even lower than in Seoul in 2025!
Suburbia and mortgages created the baby boom:
Before the modern mortgage, most people in their childbearing years were not homeowners. Just 20% of 30-year-olds owned a home. After the modern mortgage, 55% of 30-year-olds were homeowners. Marriage and childbearing soared.
This makes perfect sense. When people were able to get a home sooner, they could marry sooner, boosting fertility. …
In 1946, an entrepreneur named William J. Levitt and his company Levitt & Sons created a whole town from scratch and revolutionized housing forever. The first Levittown, created as a suburb of New York, followed a new template. Levitt purchased a 7-square-mile tract of potato and onion farms near the city and subdivided it into modest parcels. Houses were mass produced, each with its own yard and the basic amenities a family would need.
This kicked off the greatest housing revolution in history, hitting the United States from coast to coast, Canada, Australia and a number of other countries. For the first time, ordinary people could at once be part of an urban economy and have also have a house well-suited for a family.
Until the invention of the suburb, most people had an unappealing set of choices. Either be isolated on a farm or in a small town, with plenty of room to raise a family but little economic opportunity, or else move to the city, where economic opportunity was high, but you would be stuck in a crowded building that was bad for raising kids.
This had been the story of humanity since time immemorial. Cities were “fertility shredders” — bastions of opportunity but wreakers of birthrates. Although cities were economic engines, they were not self-sustaining. They had to continually draw new people from the countryside, where birthrates were higher.
Suddenly with Levitt’s great innovation, plus the automobile, everything changed. Regular people could both be integrated into the productive urban economy and have a house that was suitable for raising children, with a yard to play in and a little air gap so the noise wouldn’t upset the neighbors. And with those new mortgage programs, people could buy that house early in life, while they were still young enough to have children.
Why can’t we do this now??? (Ohh, the value of the decision maker’s housing portfolios would plummet.)
Levitt’s houses, modest though they were by today’s standards, were hugely popular. Built in assembly-line fashion, they were completed at a rate of one every 16 minutes, and 1400 houses were sold in the first three hours. By the time the first Levittown was finished in 1951, 17,500 houses had been built, accommodating nearly 100,000 people. …

The original Levittown on Long Island has aged staggeringly well, with an average selling price today of over $700,000, a 100-fold return.
People want houses. In an apartment, kids are liabilities. But if they can go outdoors and play they are ok, and it they can work on a farm they are an asset.
What do the United States, Canada, Australia, New Zealand and the Netherlands have in common? All five embraced the new decentralized suburban model with gusto. …
The Institute for Family Studies surveyed almost 9000 Americans to find out what sort of housing Americans prefer. Some 79 percent said that their ideal residence is a single-family home while just 8 percent said they prefer an apartment. …
In Sydney, Brisbane, Melbourne and Perth, the fertility rate ranges from 1.6 to 2.1 in the suburbs of single-family homes and just 0.9 to 1.1 in the apartment block-based urban core. That is up to a 100% fertility difference based on housing type and neighborhood alone. In demography, that is an absolutely enormous effect. If some pronatal policy increased TFR by just 0.1, many would consider it a win. …
So why do our New Class restrict buidling new suburbs and instead push us into high rise apartments? Can’t imagine.
The fashion these days is to upzone cities, get rid of single-family zoning, and build upward. But that has been tried, in Minneapolis, Auckland and Chicago. And in all of these cases, birthrates went down compared to nearby cities, because the type of housing being built wasn’t friendly for families.

Some 89% of Canada is government-controlled “crown land”, off-limits to building. Amid this artificial land shortage, Canada has been building large blocks of small apartments and fertility has fallen to just 1.25 births per woman. That is not a model to follow.
hat-tip David Archibald