Could tweaks to the tax code lead to more marriages — and more kids?

Fifty years ago, policymakers worried that welfare benefits were encouraging too many births outside of marriage. Today, some conservatives are making nearly the opposite argument: that government assistance programs are contributing to too few births by penalizing marriage.

“Congress should seize the opportunity to eliminate the greatest injustice in the federal income tax code: marriage penalties,” Jamie Bryan Hall, director of data analysis at the Ethics and Public Policy Center, wrote in a letter to a House committee in October. 

Over the last several years, leaders have wrung their hands over two demographic trends. Marriage rates in the US have declined dramatically — they’re the focus of recent books like The Two-Parent Privilege by economist Melissa Kearney and Get Married by Brad Wilcox, of the National Marriage Project at the University of Virginia. Meanwhile, fertility has hit record lows, prompting growing concern about demographic decline and spawning an emerging “pronatalist” movement that sees shrinking birth rates as an existential threat.

But conversations about these trends have largely remained separate. Marriage researchers tend to focus on relationship formation, family stability, and child outcomes. Pronatalists concentrate on the reasons for delaying or forgoing child birth, and the consequences that may bring. Lately though, more conservatives have argued that marriage penalties in the tax code connect these two issues — and fixing these penalties could help boost the population. 

The argument has particular appeal on the right: Fiscal conservatives generally favor reforming existing policies over creating costly new programs, while social conservatives view ending marriage penalties as supporting both wedlock and childbearing. But like the welfare debates of the past, it raises empirical questions about whether benefits actually influence family formation decisions, as well as broader ethical considerations about the government’s role in shaping personal choices.

The math on marriage

The statistical case for connecting marriage and fertility appears relatively straightforward at first. Married women have significantly higher birth rates than unmarried women, and while both groups have had fewer children in recent decades, married birth rates have declined much less. Ergo, marriage penalty critics argue that policies discouraging marriage — by pushing families above subsidy thresholds or into higher tax brackets — may indirectly suppress birth rates.

Take the Earned Income Tax Credit, designed to help low-income workers. When two working people marry, their combined income can push them above eligibility thresholds or reduce their benefits. Similar marriage penalties exist in other means-tested programs like Medicaid and housing assistance. 

These penalties were not intentionally designed to disadvantage married couples, but emerged from efforts to target benefits to the neediest while treating similar households fairly. Still, as a result, “if the typical single mom marries a typical working man, they will lose their means-tested government benefits,” Hall explained.

Some policies, like the child tax credit, largely avoid this problem by setting income thresholds high enough that most married couples keep their benefits. Food stamps take a different approach — treating all households the same whether couples are married or just living together.

While research is mixed on how well people understand these various penalties, there is some evidence they influence behavior. An American Family Survey from 2015 reported that 31 percent of Americans said they know someone who did not marry for welfare-related reasons. A more recent survey from the Sutherland Institute in Utah found that 10 percent of safety net program recipients reported deciding not to marry to avoid losing benefits. A 2022 analysis from the National Bureau of Economic Research estimated that, without marriage penalties, 13.7 percent more low-income single mothers would marry each year, and 7.5 percent more would be married by age 35. The study suggests these women typically do marry, but penalties might delay tying the knot.

Testing the theory

Some of the strongest evidence for the marriage-fertility connection comes from European programs in the 1970s and 1980s. Studies of policy experiments in Austria that involved cash payments to married couples and in Sweden with broader access to widow pensions revealed how government incentives could influence marriage rates and subsequent fertility patterns.

The subsidies proved successful at getting couples who might otherwise have postponed or forgone marriage to make it official. Importantly, these “incentivized” marriages were roughly as stable as unsubsidized ones, suggesting that policy was able to influence timing for couples already oriented toward commitment. As Lyman Stone, a conservative pronatalist demographer, put it, “Turns out people just need a nudge to say ‘yes’ to the person they’re probably gonna marry anyway.”

The fertility effects were nuanced. While marriages influenced by government subsidies had lower fertility rates than traditional, unsubsidized marriages, they still saw significantly higher birth rates than unmarried couples.  

But these European examples stand in contrast to American experience, where US programs aimed at promoting marriage have historically shown little success. And even if policymakers could effectively encourage more marriage, the relationship between marriage and fertility isn’t straightforward everywhere. India has maintained nearly universal marriage rates, even as fertility rates have sharply declined. Dean Spears, the director of the Population Wellbeing Initiative at the University of Texas at Austin, notes that India’s marriage age has also remained relatively stable, with birth rates shrinking even among women who marry before age 25.

Spears is far more skeptical that we can “nudge” people into getting married, and suggests we might be confusing cause and effect entirely. In an interview with Vox, he compared it to mistaking reduced exercise as a cause rather than a symptom of poor health. Both declining marriage and fertility rates might instead be responding to deeper social and economic shifts — from rising opportunity costs for mothers to shifting beliefs about family life.

Alice Evans, a gender inequality scholar at King’s College London, studies how economic independence and reduced stigma around being single have transformed modern relationships. Her research shows people have become more selective about romantic partners, with some choosing to stay uncoupled if compatible partners prove elusive. 

Evans believes we need better research not only on how modern life — such as social media and video games — affects relationship formation, but also on how marriage and marriage-related policies affect decisions to have children.

The price of reform

Conservatives see marriage penalty reform as a practical path forward, even though there isn’t decisive research showing that it would significantly affect marriage rates, let alone fertility.

The proposal appeals partly because it could advance multiple goals at once. For those already wanting to see more marriage and childbearing on cultural and religious grounds, fixing the penalties offers a way to promote both. That it appears less expensive than creating new programs like universal child care makes it doubly attractive.

The political challenges, however, are still substantial. Conservative economist Robert Cherry, who has worked on marriage penalty proposals for two decades, told Vox that truly eliminating these penalties could cost between $100 billion to $150 billion. More modest reforms to reduce but not entirely eliminate marriage penalties might still cost upward of $40 billion, he said. 

Some progressive policy experts see a solution that lies in deprioritizing traditional family structure. Matt Bruenig, founder of the left-wing People’s Policy Project, argues the technical fix is to just tax everyone on their personal income rather than using household income. While he supports eliminating marriage penalties to keep things fair for everyone, he’s skeptical they play a major role in declining birth rates.

Perhaps more fundamentally, there’s been little evidence of political will to address these penalties. When Republican lawmakers first considered proposals for the 2017 Tax Cuts and Jobs Act (TCJA), they explored eliminating the head of household filing status, another benefit that carries significant penalties for married couples. But the prospect of making some single mothers worse off proved too unpalatable for lawmakers to move forward with the idea.

The political landscape may shift as lawmakers prepare to revisit the expiring TCJA next year. Donald Trump ran for president on boosting birth rates, and has already elevated prominent pronatalists like Elon Musk into his new administration. His incoming vice president, JD Vance, has also placed falling fertility rates high on the conservative agenda.

Pronatalism gaining influence in conservative politics could lead not only to removing existing marriage penalties but also to actively incentivizing marriage through new subsidies, as Hungary did. Any policy response will need to address not only billion-dollar price tags but also deeper questions about whether the government should, or even can, try to steer such personal decisions in modern America.