Michael Gerson summarizes this paper, presented at this conference (other papers here). Here’s Gerson’s conclusion:

It would be nice if teen sexual behavior could be automatically changed by an abstinence lecture or a sermon. Setting those norms and expectations, however, is a small part of a larger cultural task. Moral men and women need moral communities.

This is why an abstinence program, by itself, may not accomplish much. And this is why there are no substitutes for healthy communities, beginning with families, in which young people are embedded.

In this context, the right question to ask of any government program is: does it support or "empower" families and "civil society"? Perhaps another way of putting it is: What Would Tocqueville Do?