Why the Marriage Gap Is America's Most Overlooked Inequality Crisis

The most consequential inequality in America is not the wealth gap, the wage gap, or even the racial opportunity gap. It is the marriage gap—a crisis that remains largely ignored despite its devastating consequences.

As a libertarian, I have no personal stake in whether people marry or whom they marry. Yet a new report from the American Enterprise Institute (AEI), titled Land of Opportunity: Advancing the American Dream, has forced me to confront an undeniable problem: the collapse of the American family and the role government policies have played in accelerating it.

The report, edited by Kevin Corinth and Scott Winship, examines a wide range of challenges facing the U.S., from education and crime to workforce development. But its most striking findings center on the erosion of married parenthood.

How the Marriage Gap Is Widening Inequality

Economist Robert VerBruggen, in his chapter on the decline of married parenthood, highlights staggering statistics:

• In the mid-20th century, only 5% of children were born out of wedlock. Today, that number is 40%.
• The U.S. has the highest rate of children living in single-parent households in the developed world: 23% in the U.S. compared to a 7% international norm.

VerBruggen’s research, based on the National Longitudinal Survey of Youth, reveals stark generational disparities:

• 40% of millennials from intact, two-parent families graduated from college, and 77% achieved middle-class incomes or higher.
• Among those who did not grow up in intact families, only 17% graduated from college, and just 57% reached middle-class incomes.
• Children from non-intact families are roughly twice as likely to be incarcerated, even after accounting for socioeconomic factors.

The damage extends beyond individual households. VerBruggen notes that research using tax-return data “suggests that neighborhoods with high rates of single parenthood cultivate lower social mobility, including among kids who themselves are not raised by single parents.”

Bipartisan Consensus on the Costs of Father Absence

The negative effects of single parenthood are well-documented and widely acknowledged across the political spectrum. In a 2013 review of research, Princeton University sociologist Sara McLanahan and her coauthors concluded that “studies using more rigorous designs continue to find negative effects of father absence on offspring well-being.”

Economist Melissa Kearney has demonstrated that marriage is a powerful tool for reducing poverty across all racial and educational groups. Her work shows that married parents—regardless of race or education level—experience significantly lower poverty rates than unmarried mothers.

Who Is Most Affected by the Marriage Gap?

The collapse of family stability is not happening uniformly. Winship and O’Rourke found that while marital births dropped by 29 percentage points from 1970 to 2018, the decline was far steeper for the least educated:

• 47-point drop for the bottom education quintile.
• 6-point drop for the top education quintile.

Similarly, from the early 1960s to the late 2010s, marriage rates fell by:

• 46 percentage points for the least educated young women.
• 17 percentage points for the most educated young women.

This means that those least equipped to handle the financial and emotional burdens of single parenthood are the most likely to experience it.

Marriage as a Path to Mobility

Despite these sobering trends, marriage remains one of the most effective institutions for raising children and fostering economic mobility. Yet government policies—whether through welfare incentives, tax structures, or housing regulations—often discourage marriage, particularly among low-income families.

The AEI report underscores the urgent need for policymakers to reconsider how their decisions impact family formation. As the authors note, “The marriage gap is not just a cultural issue—it is an economic and social crisis that demands attention.”