[dalnecymync]

There's a good New Yorker article from a month ago that looks at trends for abstinence.

Apparently they found the highest success rates in communities where the abstainers were a significant minority. That way, their abstinence became a strengthening factor in their minority's identity. In communities where the abstainers were a majority, the abstinence was not nearly so effective.

Also, the New Yorker cited findings that conservative communities tended to view sex before marriage as socially shameful, but pregnancy before marriage as a fact of life. In liberal communities, it's the other way round - sex is okay, but pregnancy is a sign of carelessness, inability to control your life, what-have-you.