What Can Economists Tell Us About Teenage Sexual Mores?

We’re just finishing up a new episode of the Freakonomics Radio podcast, which will likely be released tomorrow. It asks a simple speculative question: what would the world look like if economists were in charge?
One point of the episode is that economists — academic economists in particular — are generally free from the political and moral boundaries that restrict most people, and are therefore able to offer analysis or recommendations that politicians, e.g., wouldn’t go near with a ten-foot pole.
That point came to mind this morning as I was looking over a recent working paper by Jesus Fernandez-Villaverde, Jeremy Greenwood, and Nezih Guner. It’s called “From Shame to Game in One Hundred Years: An Economic Model of the Rise in Premarital Sex and its De-Stigmatization” (summary here; PDF here).
From the abstract:

Societies socialize children about many things, including sex. Socialization is costly. It uses scarce resources, such as time and effort. Parents weigh the marginal gains from socialization against its costs. Those at the lower end of the socioeconomic scale indoctrinate their daughters less than others about the perils of premarital sex, because the latter will lose less from an out-of-wedlock birth. Modern contraceptives have profoundly affected the calculus for instilling sexual mores, leading to a de-stigmatization of sex. As contraception has become more effective there is less need for parents, churches and states to inculcate sexual mores. Technology affects culture.

There is something worth unpacking in just about every sentence there. Also worth reading is the authors’ take, empirical and otherwise, on the sexual revolution:

In 1900, only 6% of U.S. women would have engaged in premarital sex by age 19. Now, 75% have experienced this. Public acceptance of this practice reacted with delay. Only 15% of women in 1968 had a permissive attitude toward premarital sex. At the time, though, about 40% of 19-year-old females had experienced it. The number with a permissive attitude had jumped to 45% by 1983, a time when 73% of 19-year-olds were sexually experienced. Thus, societal attitudes lagged practice. Beyond the evolution and acceptance of sexual behavior over time, there are relevant cross-sectional differences across females. In the U.S., the odds of a girl having premarital sex decline with [Ed.: increased] family income. So, for instance, in the bottom decile, 70% of girls between the ages of 15 and 19 have experienced it, versus 47% in the top one. Similarly, 68% of adolescent girls whose family income lies in the upper quartile would feel “very upset” if they got pregnant, versus 46% of those whose family income is in the lower quartile.

In SuperFreakonomics, we relate a parallel statistic concerning men and the sexual revolution:

At least 20 percent of American men born between 1933 and 1942 had their first sexual intercourse with a prostitute. Now imagine that same young man twenty years later. The shift in sexual mores has given him a much greater supply of unpaid sex. In his generation, only 5 percent of men lose their virginity to a prostitute.

Are we starting to understand why the U.S. doesn’t elect more economists to high office?