Are married parents better at raising kids to earn more money? American Enterprise Institute scholar W. Bradford Wilcox argues in the affirmative over at The Atlantic. Wilcox points to his own research, which "indicates that adolescents raised in intact, married homes are significantly more likely to succeed educationally and financially." Problem is, that research doesn't back up the more important point he makes later in the piece: that married parents cause kids to do better on these fronts than those raised within other family structures. Another study he cites that found a correlation between rates of single motherhood and economic mobility at the regional level is strong and significant, but still doesn’t prove the causal connection that anti-welfare activists and politicians have been assuming for ages.
Wilcox spends most of the piece describing the very real correlation between married parents and many positive outcomes for children—specifically, higher rates of college attendance, lower rates of out-of-wedlock pregnancy, and higher rates of economic mobility in places. But then he pivots to arguing that the "strong spillover effects" of marriage are causal—that the institution itself has some magical quality that produces more successful kids, independent of parenting style, financial resources, community support, and even genetics—by briefly pointing to two other studies that don't actually do much to help his case. In fact, they look at only one type of alternative family structure: kids whose parents got divorced.
To continue to debate the importance of the institution of marriage is distracting from serious efforts to actually produce happier, more successful kids.
The first, by MIT economist Jonathan Gruber, looked (PDF) at adults from states that liberalized divorce laws, finding that they were more likely to be living with divorced parents as kids, and to have lower family incomes and less education as adults. The article says little about causality; in fact, Gruber writes that the "substantial effects" he found "seem unlikely to be driven solely by parental divorce." The second, a longitudinal study of twins with divorced parents by a University of Indiana geneticist, pointed to mild causality in some areas (emotional problems, educational attainment), but not in others (drug use, early sexual activity). But, again, the article doesn’t get anywhere near isolating divorce's role enough to rewrite the consensus among the author’s colleagues. Penn State sociologist Paul R. Amato distilled that consensus in his recent literature review, which included the twins study: "Rather than ask whether divorce affects children, a more pertinent question may be how and under what circumstances does divorce affect children either positively or negatively?” It might be that the style of the split (acrimonious versus amicable) is more important than the fact of the split itself. Amato’s sweep reveals, more broadly, that after parents split, some kids do better, some do worse. But most turn out just fine.
If marriage causes children to earn more, then the logical public policy response is to encourage people to get married. If marriage merely correlates with children earning more, than there is no logical policy response, because it's possible, even likely, that other factors are more essential to a child’s upbringing. Wilcox is right to point out that kids with married parents, on balance, appear to have better outcomes by some measures. But his narrow reading of the data ignores strong countervailing evidence about the viability of alternative family structures (some of which I explored in a recent piece).
Most importantly, the genie is completely out of the bottle when it comes to the spread of alternative family structures in America. To continue to debate the importance of the institution of marriage, and not the best policies for improving the parenting skills of all parents, or creating the right economic conditions for stable families, is distracting from serious efforts to actually produce happier, more successful kids.