Would You Have a Baby If You Won the Lottery?

One of the most popular explanations for declining fertility may be wrong.

an image of playing the lottery
Illustration by Matt Chase / The Atlantic. Source: Getty.

South Korea’s fertility rate in 2022 was just 0.78 children per woman. In much of America, rates aren’t significantly higher: 0.92 children per woman in Puerto Rico and 1.36 in Vermont; in the Bay Area, it’s about 1.3. Demographers give many explanations for declining birth rates, but one of the most popular revolves around work and family. In countries such as the social-welfare states of Northern Europe, where women are given flexibility to square the demands of work with family, fertility rates are relatively high. In others, where either work or family makes excessive and incompatible demands, family loses out, and fertility falls.

Improving work-life balance is probably worthwhile and good for plenty of reasons. But very little evidence shows that it would have much effect on fertility. For example, when men help more at home, fertility doesn’t rise, one 2018 study found. And although policies to support work and family do boost fertility, their cost is pretty high for fairly modest effects (though they may have other valuable benefits: Child allowances, for example, reduce child poverty).

The ideal way to test the connection would be to randomly give some people a much better set of work-life arrangements and then see whether their family behaviors change. This would be hard to do, but as it happens, something like this random improvement in work-life balance actually occurs—when people win the lottery.

What happens when you win the lottery? Obviously, you get a considerable amount of money. Maybe you buy a new car, or a house, or pay off some debts. But you can also use your new wealth to establish a better work-life-balance: hire a cleaning service or a nanny, or cut back on work hours. Large random transfers of wealth are a nice way to test the materialist account of fertility. If receiving a pile of cash makes people have more babies, then maybe work-life balance matters a lot: More income from less demanding work would boost births. But if lottery winnings don’t increase fertility, maybe the work-life-balance theory needs some adjustment.

A team of economists studying a large pool of lottery players in Sweden found that when men win the lottery, they become a lot likelier than demographically similar lottery losers to get married (if they were lower-income and unmarried before their win), and they have more children. On its face, that supports the work-life-balance idea. But when women win the lottery, the only big change in their behavior is divorce: Divorce rates for women almost double in the first couple of years after winning the lottery.

The authors offer some straightforward explanations. When the men became wealthier, they became more desirable partners; their marriage rate increased by a third. Their increased fertility (an increase of about 13 percent) was itself largely attributable to the effect of being married, because being married tends to cause higher fertility, especially for men. The extra wealth apparently had no major effect on women’s desirability as partners, but—because Swedish law allows lottery winners to hold on to most of the winnings—had perhaps a big effect on their expectations for a postdivorce standard of living, enabling them to feel more confident about exiting a marriage.

Helpfully, the study authors showed that their conclusions matched the findings of another study of lotteries in the United States. It found that winning made both men and women more likely to marry, but that the effect was stronger for men, and that while it decreased divorce rates for men, it increased them for women. Men seem to use their newfound resources to build families, while women use them to exit families.

This seems like an inversion of common stereotypes about men and women. But reality is never so simple.

Marriage is a strong predictor of fertility for many reasons. Not least is the relationship between marital status and mental health, because mental health has a large impact on childbearing. Lottery winnings boosted male marriage and fertility not because men had unique desires for marriage and family, but at least in part because Swedish women were likelier to marry and have children with men who had more money. The effect for men is as much about women’s preferences and behaviors as men’s.

Women’s responses to winning the lottery were similarly complex. Divorce rates did not rise equally for all of them. That increase, the authors found, was concentrated among previously low-income women, those who had been married to older or wealthier men, and those who were married for three years or less. The conditions under which these women entered into marriages with these husbands could be more important than the lottery winnings. Crucially, 10 years after the lottery, winners were no more likely to divorce than other women. In other words, lottery money may have accelerated inevitable divorces rather than breaking apart couples that would otherwise have stayed together for the long term.

If people want to have more children than they can presently afford—and surveys have repeatedly suggested that they do—and societies as a whole thrive when parents of all kinds are able to raise their children in stable households, then declining birth rates are cause for alarm. And for governments seeking to reverse them by creating family policies, this research indicates that some kinds of spending may prove more effective than others.

First, it suggests that a core part of low fertility is how people (especially women) value potential partners. In surveys, women continue to report desiring much-higher-earning partners, and when men suddenly have more money, they do in fact get married more. Policy makers cannot (and should not) “solve” this by simply handing out “man bonuses.” However, understanding why men and boys are becoming more likely to fall behind women in terms of educational and professional attainment could be a core part of increasing fertility.

Second, policy makers should avoid thinking about family policy as an issue uniquely related to women. Arguments that fertility can be increased by pushing for a maximally gender-egalitarian society or by delivering family subsidies disproportionately to mothers should be reconsidered. You can’t get higher fertility without men on board. Only policies that make space for men and women to choose to prioritize parenting can support higher fertility in industrialized societies.

Third, marriage itself matters, and marriage responds to material incentives. Boosting fertility by directly targeting fertility is difficult and expensive. One reason is that marriage continues to be a gatekeeping institution for larger families. Only by removing obstacles to marriage and helping young people wed earlier and stick together can birth rates be sustainably increased. This is a challenging task, and “pro-nuptialism” has even less high-quality research on it than “pro-natalism.” However, policy makers could offer “marriage bonuses” or at least eliminate marriage penalties, like the fact that low-income people can lose their housing or SNAP benefits if they choose to combine their incomes. This much seems safe to say: Working-class people shouldn’t need to win the lottery to feel that they can afford to get married and have kids.