Whereas most scholars now agree that children raised by two biological parents in a stable marriage do better than children in other family forms across a wide range of outcomes, there is less consensus about why. Is it the quality of parenting? Is it the availability of additional resources (time and money)? Or is it just that married parents have different attributes than those who aren’t married? Thus a major theme we address in this issue is why marriage matters for child wellbeing. Although definitive answers to these questions continue to elude the research community, we’ve seen a growing appreciation of how these factors interact, and all of them appear to be involved.

. . . .The first two articles in this issue explore the link between marriage and child wellbeing. In “Why Marriage Matters for Child Wellbeing,” David Ribar theorizes that, all else equal, marriage should produce advantages that can improve children’s wellbeing, such as better coordination between parents and economies of scale that make limited resources go further. Digging more deeply, he then examines specific mechanisms through which marriage appears to improve children’s lives. Some of these have been well studied, including family income, parents’ physical and mental health, and parenting quality. Others have received less attention, including net wealth, borrowing constraints, and informal insurance through social networks. Ribar argues that although many of these mechanisms could be bolstered by public programs that substitute for parental resources—greater cash assistance, more generous health insurance, better housing, more help for caregivers, etc.—studies of child wellbeing that attempt to control for the indirect effects of these mechanisms typically find that a direct positive association remains between child wellbeing and marriage, strongly suggesting that marriage is more than the sum of these particular parts. Thus, Ribar argues, the advantages of marriage for children are likely to be hard to replicate through policy interventions other than those that bolster marriage itself.

In “The Evolving Role of Marriage: 1950–2010,” Shelly Lundberg and Robert Pollak offer a new perspective on why marriage is associated with increases in parental investments and child wellbeing. They argue that the sources of gains from marriage have changed in such a way that couples with high incomes and high levels of education have the greatest incentives to maintain long-term relationships. As women’s educational attainment has overtaken that of men, and as the ratio of men’s to women’s wages has fallen, they write, traditional patterns of gender specialization in household and market work have weakened. The primary source of gains from marriage has shifted from the production of household services to investment in children. For couples whose resources allow them to invest intensively in their children, Lundberg and Pollak argue, marriage provides a commitment mechanism that supports such investment. For those who lack the resources to invest intensively in their children, on the other hand, marriage may not be worth the cost of limited independence and potential mismatch.

The next two articles describe new family forms and their implications for children’s wellbeing. In “Cohabitation and Child Wellbeing,” Wendy Manning writes that cohabitation has become a central part of the family landscape in the United States— so much so that by age 12, 40 percent of American children will have spent at least part of their lives in a cohabiting household. Cohabitation, Manning notes, is associated with several factors that have the potential to reduce children’s wellbeing, including lower levels of parental education and fewer legal protections. Most importantly, cohabitation is often a marker of family instability, which is strongly associated with poorer outcomes for children. Children born to cohabiting parents see their parents break up more often than do children born to married parents; in this way, being born into a cohabiting parent family sets the stage for later instability. On the other hand, stable cohabiting families with two biological parents seem to offer many of the same health, cognitive, and behavioral benefits that stable married biological parent families provide. Overall, the link between parental cohabitation and child wellbeing depends on the type of cohabiting family and age of the child when he or she is exposed to cohabitation.

In “Marriage and Family: LGBT Individuals and Same-Sex Couples,” Gary Gates notes that although estimates vary, as many as 2 million to 3.7 million U.S. children under age 18 may have a lesbian, gay, bisexual, or transgender parent, and about 200,000 are being raised by same-sex couples. After carefully reviewing the evidence presented by scholars on both sides of the issue, Gates concludes that same-sex couples are as good at parenting as their different-sex counterparts. Any differences in the wellbeing of children raised in same-sex and different-sex families can be explained not by their parents’ gender composition but by the fact that children being raised by same-sex couples have, on average, experienced more family instability, because most children being raised by same-sex couples were born to heterosexual parents, one of whom is now in a same-sex relationship. Gates notes that although same-sex couples today are less likely to be raising children than same-sex couples a decade ago, those who are doing so are more likely to be raising their child since birth. This change should be associated with less instability and better outcomes for children. Gates also writes that whereas in the past, most same-sex parents were in a cohabiting relationship, this situation is changing rapidly. As more and more same-sex couples marry, we have the opportunity to consider new research questions that can contribute to our understanding of how marriage and parental relationships affect child wellbeing.

The next two articles examine disparities in marriage and review the evidence for economic and cultural explanations for these disparities. In “The Growing Racial and Ethnic Divide in U.S. Marriage Patterns,” Kelly Raley, Megan Sweeney, and Danielle Wondra review the role of structural factors, such as declining employment prospects and rising incarceration rates for unskilled black men, in accounting for the decline in marriage. Such factors clearly play a role, the authors write, but they don’t fully explain the divergence in marriage patterns. In particular, they don’t tell us why we see racial and ethnic differences in marriage across all levels of education, not just among the unskilled. The authors argue that the racial gap in marriage that emerged in the 1960s, and has grown since, is due partly to broad changes in ideas about family arrangements that have made marriage optional. As the imperative to marry has fallen, the economic determinants of marriage have become increasingly important. Race continues to be associated with economic disadvantage, and thus as economic factors have become more relevant to marriage and marital stability, the racial gap in marriage has grown.

In “One Nation, Divided: Culture, Civic Institutions, and the Marriage Divide,” Brad Wilcox, Nicholas Wolfinger, and Charles Stokes provide another look at the causes of the retreat from marriage and the growing class divide in marriage. These include growing individualism and the waning of a family-oriented ethos, the rise of a “capstone” model of marriage, and the decline of civil society.

The authors argue that these cultural and civic trends have been especially consequential for poor and working-class American families. Yet if we take into account cultural factors like adolescent attitudes toward single parenthood and the structure of the family in which they grew up, the authors find, the class divide in nonmarital childbearing among U.S. young women is reduced by about one-fifth. For example, compared to their peers from less-educated homes, adolescent girls with college-educated parents are more likely to hold marriage-friendly attitudes and to be raised in an intact, married home, factors that reduce their risk of having a child outside of marriage. Wilcox, Wolfinger, and Stokes conclude by outlining public policy changes and civic and cultural reforms that might strengthen family life and marriage across the country, especially among poor and working-class families.

The last two articles discuss policies that might increase marriage. In “The Family Is Here to Stay—or Not,” Ron Haskins makes five points. First, he writes, we might encourage marriage by reducing marriage penalties in means-tested benefits programs and expanding programs like the Earned Income Tax Credit to supplement the incomes of poorly educated men. Second, we have strong evidence that offering long-acting, reversible contraception and other forms of birth control to low-income women can reduce unintended pregnancies and nonmarital births. Third, although the “couples relationship programs” piloted by the Bush administration produced few positive results, there were some bright spots that could form the basis for designing and testing a new generation of such programs. Fourth, we could create more opportunities for disadvantaged young men to prepare for employment, and we could reduce their rates of incarceration. And, fifth, we could do more to help single mothers raise their children, for example, by expanding child-care subsidies.

In the final chapter, “Lessons Learned from Non-Marriage Experiments,” Daniel Schneider reviews evidence from social experiments to assess whether programs that successfully increased the economic wellbeing of disadvantaged men and women also increased the likelihood that they would marry. Included here are programs such as early childhood education, human capital development, workforce training, and income support. These programs were not designed to affect marriage. But to the extent that they increased participants’ economic resources, they could have had such an effect. Schneider argues that these programs tell us how much we might be able to shift the economic wellbeing of either men or women using actual as opposed to hypothetical policy tools, and thus shift marriage rates in the real world. Overall, he finds little evidence that manipulating men’s economic resources increases the likelihood that they will marry, though there are exceptions. For women, on the other hand, there is more evidence of positive effects.