Abstract
Of all pregnancies among young women in the United States, more than 60% are undesired, yet explanations for this phenomenon remain elusive. While research has investigated how pregnancy desires and intentions shape pregnancy-related behavior, only recently have scholars noted that desire for sex influences these same behaviors. Many young women simultaneously experience strong desires for sex alongside a strong desire to avoid pregnancy, but few studies have considered the extent to which young women adapt their reproductive behaviors in response to these potentially competing desires. Using novel weekly panel data, this analysis assesses how desires for sex may moderate the effect of the desire to avoid pregnancy on a young woman's sexual behavior and contraceptive use. Findings suggest that when a woman strongly wants to avoid pregnancy, she is less likely to have sex and more likely to use hormonal or coital contraceptives. As her desire for sex increases, however, she is instead more likely to have sex and use hormonal contraceptives. If she does not use hormonal methods, she is less likely to use coital contraceptives when she has intercourse. These findings highlight the importance of recognizing the desire for sex as a behavioral modifier for avoiding undesired pregnancy in the transition to adulthood.