# When abstinence increases prevalence

## TL;DR

This paper shows that increased abstinence preferences among potential partners can unintentionally raise infection prevalence due to adverse selection, highlighting complex effects on public health and welfare.

## Contribution

It introduces a model demonstrating how abstinence preferences can paradoxically increase infection rates through adverse selection mechanisms.

## Key findings

- Increased abstinence preference raises infection prevalence.
- Prevention and treatment decrease infection rates.
- Adverse selection drives the paradoxical effect.

## Abstract

In the pool of people seeking partners, a uniformly greater preference for abstinence increases the prevalence of infection and worsens everyone's welfare. In contrast, prevention and treatment reduce prevalence and improve payoffs. The results are driven by adverse selection: people who prefer more partners are likelier disease carriers. A given decrease in the number of matches is a smaller proportional reduction for people with many partners, thus increases the fraction of infected in the pool. The greater disease risk further decreases partner-seeking and payoffs.