Quaife Matthew, Vickerman Peter, Manian Shanthi, Eakle Robyn, Cabrera-Escobar Maria A, Delany-Moretlwe Sinead, Terris-Prestholt Fern
Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK.
Wits RHI, University of the Witwatersrand, Johannesburg, South Africa.
Health Econ. 2018 Oct;27(10):1550-1566. doi: 10.1002/hec.3784. Epub 2018 Jun 21.
Evidence suggests that economic factors play an important role in commercial sex work, in particular that condomless sex commands a price premium relative to condom-protected sex. This paper explores whether the use of a new HIV prevention product, with 100% efficacy but modeled after pre-exposure prophylaxis (PrEP), could change the price and quantity of condomless commercial sex supplied. We collected stated preference data from 122 HIV-negative female sex workers in urban South Africa, using a repeated choice experiment to simulate the impact of using PrEP on choices. Results suggest that the price premium for condomless sex would decrease by 73% with PrEP use and the quantity of condomless sex is predicted to increase by a factor of 2.27. Act price does not significantly affect choices without protection but strongly influences choices under full HIV protection. The utility offered by condoms reduces by around 15% under PrEP use. Because new HIV prevention products do not protect against other STIs or pregnancy, the unintended consequences of introducing HIV prevention products should be closely monitored, whereas users should not face stigma or blame for reacting rationally to exogenous changes to market conditions.
有证据表明，经济因素在商业性交易中发挥着重要作用，尤其是无保护性行为相对于有安全套保护的性行为能获得价格溢价。本文探讨了一种新型艾滋病毒预防产品（其功效为100%，但仿照暴露前预防药物[PrEP]）的使用是否会改变无保护商业性交易的价格和数量。我们从南非城市的122名艾滋病毒阴性女性性工作者那里收集了陈述性偏好数据，采用重复选择实验来模拟使用PrEP对选择的影响。结果表明，使用PrEP后，无保护性行为的价格溢价将降低73%，预计无保护性行为的数量将增加2.27倍。实际价格在无保护情况下对选择没有显著影响，但在完全艾滋病毒保护情况下对选择有强烈影响。在使用PrEP的情况下，安全套提供的效用降低了约15%。由于新型艾滋病毒预防产品不能预防其他性传播感染或怀孕，因此应密切监测引入艾滋病毒预防产品的意外后果，而使用者不应因对市场条件的外部变化做出合理反应而面临耻辱或指责。
