Amy L. Wax — a professor of social welfare law at U Penn Law School has a great piece in the Journal today (Reg req’d). She tackles the myth that low-income alone leads to family breakdown. An excerpt:

What can we learn from these tales of working-class city life and the demographic facts behind them? First, the decades-old demise of clear standards following the sexual revolution, at worst a mixed blessing for the well-off, has hit the less privileged hard. The disparities in family structure suggest that people are not equal in their ability to handle newfound sexual freedom. The well-heeled don’t often defend the 1950s, but they haven’t left them entirely behind. That behavior differs by social position should come as no surprise. Foresight and capacity for self-governance are qualities that make for economic success. They also make for orderly families.
Second, marital and sexual behavior depend more on mores than money. Restraint and social norms, rather than economic circumstances, best account for class differences. As Christopher Jencks and David Ellwood at Harvard have noted, economic factors fail to explain why privileged women, who are best equipped to go the single-motherhood route, insist upon marriage before children. Work by sociologists indicates that men may be the key. What we know about why marriages endure suggests that better-off men more often honor monogamy and strive for sexual fidelity. In family life, as in education, degrees matter: The rare or hidden lapse is worlds apart from infidelity as a way of life.
Left-leaning scholars adamantly resist this picture. They insist that family breakdown is all about economic opportunity. The problem is not that people are behaving badly or that — heaven forbid — one class is more prudent than another, but that our policies are inadequate. Material conditions, not moral commitments, are the source of domestic chaos. To change behavior, we must give the poor more resources.
Decades of experience belie this view. Poor relief and welfare policy, whether strict or lenient, can’t rescue disintegrating families. Rather, as Mr. Jencks and others have shown, the very opposite is true: Wise behavior can secure economic well-being. Men and women who stick together, stay out of trouble, and work steadily are rarely poor, and their children surmount poverty as well. Public money and policy gimmicks are no substitute for good conduct.