Scott J. South

Migration from Mexico to the United States results in numerical imbalances between men and women in the communities left behind, but little is known about how these imbalanced sex ratios in Mexican communities affect family formation behavior. Using two waves of data from the Mexican Family Life Survey (MxFLS) and 2000 Mexican census data, we examine how the sex composition of the municipality population is associated with the likelihood that Mexican women and men marry. Consistent with demographic-opportunity theory, but not sociocultural theory, results from logistic regression analyses show that men’s probability of marrying is positively associated with the numerical availability of eligible women in the municipality population. Consistent with the argument that many Mexican migrant men, but not migrant women, remain eligible partners for those who remain in Mexico, the sex composition of the municipal population is significantly associated with men’s but not women’s likelihood of marrying.

Fewer young adults are engaging in casual sexual intercourse now than in the past, but the reasons for this decline are unknown. The authors use data from the 2007 through 2017 waves of the Panel Study of Income Dynamics Transition into Adulthood Supplement to quantify some of the proximate sources of the decline in the likelihood that unpartnered young adults ages 18 to 23 have recently had sexual intercourse. Among young women, the decline in the frequency of drinking alcohol explains about one quarter of the drop in the propensity to have casual sex. Among young men, declines in drinking frequency, an increase in computer gaming, and the growing percentage who coreside with their parents all contribute significantly to the decline in casual sex. The authors find no evidence that trends in young adults’ economic circumstances, internet use, or television watching explain the recent decline in casual sexual activity.

Although Black and Hispanic young adults in the U.S. are less likely than Whites to move out of the parental home and more likely than Whites to return, reasons for these differences have not been clearly identified.