Stable, two-parent families have always mattered for kids. But today, we have new evidence that they may matter more than ever.

A new study from the Institute for Family Studies (IFS) indicates that an intact family is increasingly tied to the educational, financial, and social welfare of children. Meanwhile, family instability appears to harm kids more than it used to. Growing up with two parents made a bigger difference for Millennials than for Boomers.

This new report co-authored by one of us (Wilcox) comes on the heels of an important new book by Brookings Institution economist Melissa Kearney, The Two-Parent Privilege, showing that American kids do better when raised in a two-parent family. Kearney’s exhaustive social-science research has kneecapped left-wing arguments that marriage and family stability don’t matter for children.

“Avoiding this topic is counterproductive,” Kearney told the Conversable Economist. “Denying the importance of family structure and the role of families to children’s outcomes and economic mobility is just dishonest, based on the preponderance of evidence.”

Even so, the share of Americans who think marriage and a stable family are not important for children is growing. Gallup found that from 2006 to 2020 the share of adults who reported that it is “important” for unmarried couples who have had a child together to “legally marry” dropped from 76 percent to 60 percent, a trend that is concentrated among college-educated liberals. In fact, in her book, Kearney reports that it has been especially tough to raise the family-structure issue in the elite circles she travels in, which is not surprising, given that only 30 percent of college-educated liberals agree that children are “better off” with married parents, according to one recent survey.

Nevertheless, the science detailed in her book shows that, to the contrary, marriage and stable two-parent families matter a great deal for children. But what is striking about the new IFS report is it conveys growing evidence that family structure matters more than ever for today’s children.

In analyzing the 1979 and 1997 cohorts of the National Longitudinal Survey of Youth, the report finds not only that both Boomer and Millennial generations had higher college-graduation rates and income averages among those who grew up with both parents in comparison with their peers who didn’t but that the relationship between family structure and success was different for these two cohorts. And not in the ways that mainstream media would have you think.

On the education front, today’s Millennials from stable, two-parent homes were 23 percentage points more likely to graduate from college, compared with their peers from unstable homes. Boomers from stable families enjoyed only a 14-percentage point advantage in this regard. What’s more, the bigger family structure advantage for Millennials held even after controls for race, parental education, and other factors were added to statistical models exploring this relationship.

What about finances? Millennials from intact families were 20 percentage points more likely to reach the middle class or higher, compared with peers from non-intact families. Boomers raised in a stable, two-parent family saw their odds of reaching this level of economic success increase by only 16 percentage points if they. Again, this generational difference was statistically significant in models controlling for race, parental education, and a number of other factors.

Three factors may help explain why a stable, two-parent family seems to matter more than ever for children, according to this new IFS study:

Dads are more involved in their kids’ lives today than in past generations, meaning kids have a lot more parental attention in two-parent households than they used to.

Income levels for two-parent families are higher and more stable than for single-parent households.

There is evidence that the growth in low-conflict divorces in recent decades has negatively impacted children. These splits are far more damaging to a child who can’t understand why a parental relationship that seemed good enough has ended.

What we have, then, is a marriage paradox. On the one hand, marriage has lost ground in the popular imagination and in practice. But on the other hand, for the sake of the kids at least, marriage seems to matter more than ever.

Brad Wilcox is the Future of Freedom Fellow at the Institute for Family Studies and the author of the forthcoming book Get Married: Why Americans Must Defy the Elites, Forge Strong Families, and Save Civilization. David Bass is communications director for the Institute for Family Studies.