Marriageable mates: patterns in partnership formation and sero-sorting in rural Uganda

HIV risk is shaped as much by the partners we choose as by the sex we have. In the absence of widespread uptake of couples testing, most partnerships lack information about the prospective partners’ sero-status. This paper seeks to determine how effective individuals are at managing this uncertainty. Previous research suggests that individuals use selective partnership formation to select against risky attributes, such as age, mobility, and widowhood. What remains unclear, however, is how accurate people are at selecting sero-negative partners. This paper examines trends in marital partnership formation and sero-sorting over 13 years using census data from a sero-surveillance site in Southwestern Uganda. Taking into account population composition changes over time, this paper finds evidence of intra-group preference among both sero-positives and sero-negatives. This paper provides the first quantitative analysis of sero-sorting and the effectiveness of partnership selection as an HIV prevention strategy.