The relentless decline in global fertility accelerated during Covid-19, pushing humanity closer to failing to achieve a replacement-level birthrate—the point below which a new generation is smaller than the previous one. Though the U.S. for decades had defied a trend that saw several prosperous industrial nations fall short of that benchmark, the so-called birth dearth recently has reached the United States. The Congressional Budget Office estimates that, in 2020, the number of children born per adult woman in the U.S. hit an average low of 1.64. Rather than trending up after Covid, the total fertility rate fell to an all-time low of 1.62 last year, well below the replacement rate of 2.1 children per women. 

There’s plenty of speculation about the cause of collapsing birthrates at home and abroad. Population experts attributed the first big declines, seen during the Industrial Revolution, to scientific advances that lowered infant mortality and increased birth-control options, and to prosperity-boosting technological gains that made children as workers less valuable to parents. But as birthrates kept falling below replacement levels in the decades and centuries that followed, observers have focused on factors like the decline in marriage, increases in divorce, and even rising housing prices as possible explanations for the globe’s fertility slowdown.

Of course, many factors influence national birthrates. One thing that stands out in the United States, however, is how fertility differs among the states—ranging from a low of 1.27 in Vermont to nearly replacement-level in South Dakota. Notably, the states with the highest birthrates are overwhelmingly Republican, and those with the lowest are disproportionately Democratic. What, if anything, can this tell us?

While it can be perilous to make quick assumptions about correlations, there is an unmistakable correspondence between states’ birthrates and their political affiliation. The 17 states with the highest general fertility rates are all designated by Cook Political Report as Republican, or GOP-leaning, including such Republican strongholds as North Dakota, Nebraska, Louisiana, Utah, and Texas. By contrast, the bottom six states—and nine of the ten states with the lowest fertility rates—are all either Democratic or Democratic-leaning. (Nevada, which Cook deems marginally Republican, is the one exception, with the tenth-lowest birthrate.) Others near the bottom include Rhode Island, Oregon, Massachusetts, Washington, and California. Only two Democratic states have birthrates above the national average, compared with 20 Republican states with above-average fertility.

Some states have switched places over time. After the U.S. national rate declined to 1.73 births per woman in 1976, it began climbing again, reaching replacement level in 1990—a rare rise among countries. U.S. birthrates then stayed near or slightly above that level for some 20 years before a slow but steady decline following the Great Recession of 2008, which accelerated during Covid. Some states, however, have fallen further and faster than others. California has experienced the steepest decline, from a birthrate of 2.47 in 1990, then the nation’s third-highest rate, to just 1.47, the ninth worst today. Utah’s rate has also tumbled since 1990, but unlike California’s, it remains well above average, while rates in Indiana, North Dakota, and Kentucky have fallen the least.

Marriage is certainly a key element in understanding state-level fertility data and birthrates more generally. While women may have children outside of marriage, studies consistently show that married couples are more committed, stay together longer, and have more children than do unmarried individuals. American marriage rates, which had been dropping slowly for years, began a sharper decline in 2017, and plunged further in the first year of Covid. Today, the number of marriages per 1,000 people in the U.S. is 38 percent lower than in the early 1990s, as barely more than half of all adults are married. Like fertility rates, however, the story differs per state, and a politically color-coded map of state marriage rates resembles that of state fertility rates. Nine of the ten states with the lowest marriage rates, and eight of the states with the highest percentage of never-married people, are Democratic, low-birthrate states.

Housing prices are another possible cause of cross-state fertility gaps. Several studies have linked industrialized countries’ low fertility rates to rising housing costs, as inflated prices cause couples to delay marriage and limit their number of children. One study even connected rising interest rates, which boost homeowners’ mortgage payments, to declining fertility.

Housing costs vary greatly by state. Economists associate levels of government regulation, especially on zoning, to high housing prices. For example, a recent paper examined the effects of the so-called zoning tax (the added cost of zoning regulations) in 24 metropolitan areas. The researchers found that those areas with the highest zoning taxes were overwhelmingly cities in Democratic states—including San Francisco, New York, Seattle, and Washington, D.C. Those with the smallest zoning premium, by contrast, were red-state cities like Cincinnati, Dallas, Atlanta, and Charlotte. No wonder, then, that all ten states with the lowest median housing prices are Republican and largely boast above-average fertility rates, while seven of the ten states with the highest housing prices are low-fertility and Democratic.

States’ responses to the recent pandemic also overlap with their fertility rates. Historically, societies have seen major declines in fertility during periods of economic and social stress, such as the two world wars and the Great Depression. The Covid pandemic certainly qualifies as such a traumatic time, and given that partisan differences in states’ handling of that crisis correlate with birthrates, it’s possible that their varying policies had some effect on fertility. Republican states recovered quickest economically from the Covid shutdowns, adding hundreds of thousands of new jobs some two years after pandemic lockdowns began, even as Democratic states were still short more than 1 million jobs, according to one analysis. A working paper from the National Bureau of Economic Research charted Covid-era economic and social outcomes, including how quickly schools reopened, and found that 17 of the top 20 states in terms of recovery were Republican, while nine of the ten states with the worst outcomes were Democratic. (The exception, again, was low-fertility Nevada.)

Given global fertility declines, the question is whether differences in state outcomes can illuminate how to stabilize births. Many low-birthrate countries, such as Japan and Western European nations, have tried government-driven, so-called pro-natalist policies—like mandating maternal leave, offering tax breaks for having kids, and subsidizing child care—with little success. In the U.S., some policy experts are campaigning to expand the federal child tax credit to support families, while some states and cities have also mandated that businesses grant leave to new parents. Immigration advocates, meantime, claim that new residents can solve our population woes, though studies in Europe of countries with significant foreign-born populations, like Austria, have found the “immigration bounce” is small because new arrivals quickly adopt their new country’s fertility practices. In America, many new arrivals are poor, low-educated migrants who require significant government subsidies—creating other sorts of problems.

Perhaps the most important thing that government can accomplish when it comes to fertility is to do no harm. Recent American social policy may well have discouraged marriage, especially among low-income recipients of federal and state government aid. Similarly, local governments played a decisive role in pushing up American housing costs—and creating the disincentives to having children that those costs present.

Many fertility scholars note that birthrates began plunging as countries grew richer. They assume that prosperity is linked to people having more options in life, which makes having children less desirable. But prosperity also brings with it bigger and more ambitious government, with more social spending, more regulation, more complexity in taxes—and more unintended social consequences. That’s another obvious difference between Republican and Democratic states in America: the ones with lower fertility rates have more government. Perhaps that is part of the problem.

Photo: vasiliki/E+ via Getty Images


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