Partnership duration and concurrent partnering: implications for models of HIV prevalence

Researchers and policy makers have argued that long-duration concurrent relationships promote the spread of HIV. The concurrency hypothesis proposes that concurrent partnering, particularly as manifested in formal and informal polygyny, is a primary contributor to the spread of HIV in sub-Saharan Africa. We investigate claims that agent-based models of concurrent partnering support this hypothesis. Specifically, we explore how assumptions about the duration and network structure of sexual partnerships affect the results of agent-based models of HIV propagation. We offer new support for the contention that long-duration concurrent partnering can be protective against HIV transmission rather than promoting it. Additionally, we argue that the focus on concurrency has misdirected attention away from the key role of exclusivity.