Social context and sexual intercourse among first-year students at selective colleges and universities in the United States

• I examine institutional and peer-group effects on college student sexual behavior.
• Both institutional and peer-group factors affect college student sexual behavior.
• Friends' values are especially salient for sexual behavior.
• Sex market framework is helpful for analyzing sexual behavior among college students.

Most examinations of sexual behavior ignore social context. Using panel data from the National Longitudinal Study of Freshmen, a panel study of 3924 students at 28 selective colleges and universities, I examine how institutional and peer-group characteristics influence the incidence of sexual intercourse among students during their freshman year. Students who enter college as virgins are more likely to have sexual intercourse on campuses where women comprise a higher proportion of the campus population and on campuses that are more academically rigorous. Students who had sex prior to college are less likely to have sex in college when campuses are more residential. Moreover, having friends who value religion and partying affects the likelihood that a student will have sex irrespective of their prior virginity status. These findings highlight the importance of social context for sexual behavior among college students and in the general population.