It's something millennials hear again, and once more, and again: Their delay in starting families, and their inability to afford a home, represent their collective failures as a generation.

We're slowly starting to sympathize that this may non be their fault (information technology might exist capitalism's). And a team of economists have now crunched the data proving that zoning and restrictive country-use regulations–forces that contribute to making housing so expensive in cities similar San Francisco and New York–are really driving fertility rates downwards.

In a recent paper co-authored with Harvard Kennedy School PhD candidate Lauren Russell, Daniel Shoag, a Kennedy School and Case Western Reserve professor, constitute "a significant human relationship between land-use restrictions and fertility rates across all measures and geographies." Shoag and Russell determined the relative restrictiveness of a city'south land-utilize policies by the number of cases brought to court around housing issues; they crossed that data with listings similar the Wharton Residential Land Use Index to go far at a complete picture of a city'south zoning codes and housing stock. When overlayed with fertility data from the CDC, they found that the cities and towns that actively stifle or restrict development are seeing fertility rates, especially among immature women, plummet.

Nosotros know this instinctively. Stories abound well-nigh immature tech workers in major cities living in tiny apartments that could never accommodate a family. Fifty-fifty for the relatively well-off in these cities, the costs of relocating to a larger dwelling are prohibitive enough that they ofttimes simply forgo, or filibuster, starting a family unit until much later in life: Birth rates among women aged 20 to 24 (once, the virtually likely time to start having a family) declined by 4% from 2006 to 2016. In that aforementioned time frame, fertility rates amongst women aged 35 to 39 rose slightly.

[Photo: Conner White potato/Unsplash]

These findings, Shoag tells Fast Company, fall within "a larger shift in the U.South. economical mural abroad from ii trends that had held true for a very long fourth dimension." 1 tendency was that for 100 years, incomes per capita in historically poorer states had grown more quickly than incomes in wealthier states, and the gap between the two was slowly endmost. And the other, Shoag says, was that people from poorer states would often move to richer places in search of higher wages. Over the last xxx or and then years, though, both trends take abruptly disappeared.

"The disappearance is intuitive," Shoag says. "If yous think of places in the country that are growing fastest in terms of population, y'all remember of places like Texas, Central Florida, Utah. You lot don't call up San Francisco." That's considering, Shoag says, cities like San Francisco, which is notorious for a stagnant housing stock, aren't building enough to accommodate growth. The population in places like San Francisco and New York moves, to be sure, only it'southward more a affair of turnover–wealthier, more than educated people moving in and displacing lower-income, less skilled workers–than it is a thing of growth. And opposite to the previous trend, which held that places like Alabama and Mississippi were where wages were growing the fastest, we're now seeing the steepest climbs in income in those aforementioned cities–San Francisco, New York, Seattle–that aren't building plenty to accommodate growth.

So in a sense, the wealthiest cities, by restricting their housing supply, are driving rents upward, concentrating their populations downwards to the people who can afford them, and making it increasingly harder for people with fewer resources to motility there and stay at that place.

Essentially, moving to places like San Francisco or Seattle requires a series of requirements that you lot be well-educated plenty to work in industries, increasingly concentrated in those areas, that demand it; that you be willing to vanquish out a large portion of your income on housing; and that as a result, you lot minimize your external expenses and obligations to others.

And that, of form, precludes introducing the massive expense that is having a kid.

Which brings us back to the decline in fertility rates. This is a tendency that'southward largely concentrated in major cities, but the wage stagnation in other parts of the country too creates a barrier for new parents. Economists like Shoag are particularly concerned most this reduction in fertility. Fewer children being born now–especially in the wealthiest cities–ways there volition be fewer people to prop up the economy in the years to come up, and fewer people to support the population aging now. Nosotros've substantially created a system that makes reproduction such a burden on people that the system volition soon no longer be able to reproduce itself (again, this is a problem with capitalism).

Cities, Shoag says, could practise more to support fertility rates, population growth, and opportunities for lower-income people to move in that location and thrive by building more and affordable housing, and alleviating some of those country-use regulations that take fabricated those three conditions so difficult to maintain over the past several decades. Even measures like increasing the minimum wage, which San Francisco, New York, and Seattle accept championed in recent years, will accomplish picayune if those cities don't besides build housing. "There's only room for X number of people," Shoag says. "If a city creates fifty,000 new jobs at a good wage just doesn't update zoning codes or add more than housing, that'southward l,000 people that'll be pushed out." With conditions this restricted, it's no wonder that the idea of introducing new babies into the mix is being pushed further and farther down the line.