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Discussion about the great American baby bust often seems meant to induce fear. The concern is that with fewer babies, economic growth will plummet, and too-few workers will have to shoulder the burden of an aging population. But if I’m being honest, the latest news about the drop in American births did not raise my blood pressure much.

Maybe it’s because I, myself, am kind of “eh” on kids in general. Maybe I’ve just been watching too many men beseech women to do their feminine duties on Handmaid’s Tale. So American women are opting out of parenting? Good for them! More time for Netflix, making money, reading my articles—to name just three very pleasurable activities that don’t cause stretch marks.

Or at least, so I thought. I recently came across something that’s made me sit up and pay attention to fertility rates: There is research linking falling fertility to rising populism.

Definitions of populism vary, but it’s often thought to be a political philosophy in which “the people” are pitted against elites and outsiders in a struggle for domination. The rhetoric of President Trump is often considered to be populist.

Here’s how Philip Auerswald, a George Mason University professor, and Joon Yun, a hedge-fund manager, explain this connection in a recent New York Times op-ed:

In the world’s largest cities, where populations are densely concentrated and growing, economies are generally thriving and cosmopolitanism is embraced. Where populations are sparse or shrinking, usually in rural places and small cities, economies are often stagnant, and populism sells.

Why does it hold such appeal in these places? Nativist, nationalist rhetoric—“Make America (or Whatever Other Country) Great Again”—appeals because it promises to restore the rightful economic and cultural stature of “common people” ... Where populations decline, populists arise—more often than not, promising to reverse history and restore past glory if not demographic dominance.

The problems typically associated with falling fertility are a struggle to pay for Social Security and Medicare in the long run. Fewer babies today means fewer workers in the future, which means less money in the Social-Security pot.

These might seem like relatively manageable threats: We could simply raise immigration quotas to boost the number of “missing” workers, for example. But it’s the very arrival of these immigrants that might fuel populist sentiment. The way this would work, as my colleague Derek Thompson has explained, is in a sort of doom loop: Population plummets, immigration increases, people get scared by the influx of newcomers, they become more xenophobic, and thus more inclined to support nationalist parties.

“There is a growing body of evidence that as rich majority-white countries admit more foreign-born people, far-right parties thrive by politicizing the perceived threat of the foreign-born to national culture,” Thompson writes.

It’s not clear that simply increasing the number of immigrants to the United States will tilt people further to the populist right. For one thing, societies and cities with large numbers of immigrants don’t necessarily harbor more populist sentiments, as the psychologist Stephan Lewandowsky explains at The Conversation:

For example, in 1978, when net migration to the U.K. was around zero, up to 70 percent of the British public felt that they were in danger of “being swamped” by other cultures. Conversely, in the early 2010s, the white Britons who were least concerned about immigration were those who lived in highly diverse areas in “Cosmopolitan London.”

Instead, it might have more to do with how fast the immigrants come in, where they end up living, and how well they’re received. Just before the 2016 election, The Wall Street Journal found that it was counties that were diversifying more quickly than the rest of the country that were more likely to be drawn to Donald Trump. In other words, these weren’t places like Miami and Los Angeles, where immigrants have long made up much of the population. These are places like Arcadia, Wisconsin, where the “diversity index” had increased by more than 150 percent in recent years.

There, “Mr. Trump’s pledge to build a wall along the Mexican border and prioritize jobs for American workers has struck a chord with some whites uneasy over rapidly changing demographics,” the WSJ reporters Janet Adamy and Paul Overberg wrote. “They said they are worried illegal immigrants are crowding schools and unfairly tapping public assistance, problems they believe Mr. Trump would fix.”

That vague sense of “unease” seems to be the crux of nationalist and populist sentiment. Rather than being predominately motivated by racism—though it often is that—populism seems like a wide-ranging desire to return to the glory days, before things changed so much. In a 2011 academic article, Anna Sofia Lundgren and Karin Ljuslinder describe how populism and an aging population might be related. Populist rhetoric requires an enemy that is meant to be defeated, they write, and in this case, that enemy is a lack of native births—a trend that’s portrayed as unnatural:

What is central to populism is not just the constitution of an enemy, but also the location of that enemy outside of the system. In the studied case this meant setting aside the possibility that the processes of population ageing are inherent to modern societies. For example, modern aspects such as improved and increasingly technology-intensive equipment, more expensive medical care, better living conditions, norms of ‘‘finding oneself’’ before starting a family, increased demands for higher education and so on, all contribute to higher average age rates and lower fertility rates. These are all things that most people find central to an individualised democratic modern lifestyle and which they do not wish to change. By ignoring how our way of living and thinking contribute to a situation of population ageing, populist discourse produces population ageing as not only a threatening enemy, but also as an external enemy that is conceptualised as inexorable.

It doesn’t seem to matter if the immigrants that come in don’t actually displace native-born people, or if the lower birth rate reflects the true desires of the native-born women. As Lewandowsky writes, populism seems to have more to do with how people feel about their place in the world relative to others, rather than where they actually sit:

There is now reasonably consistent evidence that populism thrives on people’s feeling of a lack of political power, a belief that the world is unfair and that they do not get what they deserve—and that the world is changing too quickly for them to retain control. Whenever people attribute the origins of their perceived vulnerability to factors outside themselves, populism is not far away.

Finally, a study from 2016 in Belgium underscored how the powerlessness, the rapid demographic change, and the xenophobia all fuel a kind of anarchic and bleak perspective on the country’s future. It found that “populist attitudes are grounded in a deep discontent, not only with politics but also with societal life in general.” People who feel more vulnerable in various ways, that study suggests, are drawn toward populism as a sort of coping strategy.

This is where I could see falling birth rates playing a role in populism. Seeing your small town vanish, watching your friends grow old and die and not leave anyone behind—it can make you feel kind of, well, vulnerable. Places don’t tend to feel complete without young people. The desire to avoid that absence is natural, but left unchecked, it can be xenophobic, too. In the most extreme cases, it might make you drawn to the promise that your kind of people will rise again.

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