The Promise and Limits of Nudging under Stigma: Experimental Evidence on Menstrual Cup Adoption and Use in Botswana

Many welfare-improving technologies in low- and middle-income countries exhibit low take-up even when prices and access barriers are minimal. This paper studies this phenomenon in the context of menstrual health in Botswana, a domain characterized by stigma and where reusable menstrual health technologies were virtually unknown. We conduct a randomized survey experiment that independently randomizes persuasive information and default provision of a menstrual cup in a 2×2 design. Defaults substantially increase adoption at the point of choice, while persuasive information alone has little effect. When combined, the two interventions generate large effects on initial adoption, with persuasive information substantially amplifying the impact of default product provision. However, qualitative follow-up conducted 15 months later reveals a sharp initial adoption–usage gap: most respondents who selected the cup under the default did not go on to use it. The evidence points to learning costs, embodied discomfort, and stigma as the primary barriers to sustained use. The findings highlight both the power and the limits of behavioral nudges in novel and stigmatized product markets, and underscore the importance of distinguishing initial adoption from durable technology use.