"Now we have this huge penalty," says Carol Tremblay, professor of economics at Oregon State University, who has studied teen sexual behavior. "I think kids are taking that into account."
The economic model also predicts that as the health cost of vaginal sex increases, people will engage in more oral sex. In 2002, 13% of boys and 11% of girls ages 15 to 17 had had oral sex with the opposite sex, but not intercourse, according to the CDC. And many of those teens believe the practice is safe.
The Kaiser Family Foundation found troubling results in adolescent attitudes toward the practice. Some 26% of teens believed, falsely, that a person cannot become infected with HIV through oral sex, and an additional 15% said they didn't know whether it was possible.
"Is fear of sex a good thing or a bad thing?" says Thomas J. Coates, a professor in the division of infectious diseases at UCLA. "The answer is probably 'yes.' "
Fear, it seems, has taken up residence in the bedroom, the clandestine motel room and the back seat of the family car -- right alongside romance and desire.
