A new study from the Journal of Economic Perspectives suggests that teen childbearing is more an outcome of poor economic circumstances than a cause. As the authors assert:

Taken as a whole, previous research has had considerable difficulty finding much evidence in support of the claim that teen childbearing has a causal impact on mothers and their children.

What research does imply, however, is the central importance of marriage in general. Married couples — at all education levels — are significantly less likely to be poor. Controlling for socioeconomic factors, children from married-parent homes are also less likely to be at risk for a variety of negative outcomes such as behavioral problems, incarceration, and substance abuse.

And although teen childbearing is problematic, the growth of births to unmarried mothers in the United States — which now stands at over 40 percent — for the most part cannot be attributed to the foibles of youth of high-school age. Rather, the cause is the collapse of marriage among young adults in lower-income communities — and increasingly in middle-income ones too.

In fact, less than 10 percent of births outside marriage occur to women under age 18, while nearly three-quarters are to women between 18 and 29.

Nevertheless, single motherhood is much more pervasive among lower-educated American women than their college-educated peers. Although less than 10 percent of non-marital births are to women with a college education, nearly 70 percent of births to women without a high-school diploma and just about half of births to women with only a high-school education occur outside marriage.

As Brad Wilcox, director of the National Marriage Project at the University of Virginia, explains, the result is that “more affluent Americans are now doubly privileged in comparison to their moderately educated fellow citizens — by their superior socioeconomic resources and by their stable family lives.”

Highly educated Americans (those with at least a college degree) tend to follow the traditional pattern of getting married prior to having a child. But in lower-income America, marriage and parenthood have become disconnected — creating a growing inequality divided along the lines of marriage and education.

Unfortunately, rather than informing young men and women in lower-income communities of the consequences of unwed childbearing, we have had a “pervasive social silence” on this matter for decades, as my colleague Robert Rector asserts.

Charles Murray, author of the recent Coming Apart: The State of White America, 1960–2010, similarly notes that “politicians and media eminences are too frightened to say . . . [that] non-marital births are problematic.”

Admittedly, pushing back the tide of unwed childbearing and addressing the breakdown of marriage is no easy task. But it has to begin somewhere. Breaking this “social silence” surrounding the consequences of unwed childbearing is a good place to start.

Instead, the dominant approach has been to promote greater access to birth control. But a supposed lack of birth control doesn’t explain why many of these women choose to become pregnant. As the researchers of this study and other sociologists point out, many women in low-income communities who become pregnant do so because they want to have children, or at least are ambivalent about it.

Another approach has been to expand the federal welfare state. Yet, despite a nearly1,600 percent increase in welfare spending since the 1960s, unwed childbearing in the United States has more than quadrupled.

Births outside marriage are the greatest factor in poverty among households with children today. Yet, this trend abounds not only in lower-income communities but is finding its way into the heart of Middle America. Wilcox warns:

If marriage becomes unachievable for all but the highly educated, then the American experiment itself will be at risk. The disappearance of marriage in Middle America would endanger the American Dream, the emotional and social welfare of children, and the stability of the social fabric in thousands of communities across the country.

With more than five decades of nearly steady increases in the unwed birthrate, it is time to stop tiptoeing around the issue. All sectors of society should take action to reinforce the institution that is most crucial to the prosperity of individuals and to the entire nation.