Prostitution and the sex discrepancy in reported number of sexual partners

One of the most reliable and perplexing findings from surveys of sexual beh avior is that men report substantially more sexual partners than women do. We use data from national sex surveys and studies of prostitutes and their clients in the United states to examine sampling bias as an explanation for this disparity. We find that prostitute women are underrepresented in the national surveys. Once their undersampling and very high numbers of sexual partners are factored in, the discrepancy disappears. Prostitution's role i n the discrepancy is not readily apparent because men are reluctant to ackn owledge that their reported partners include prostitutes.