Promotion of (interaction) abstinence increases infection prevalence

This paper analyses how promoting social distancing changes infection rates and welfare. In the pool of people seeking personal contacts, a greater preference for distance 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 matches are likelier disease carriers. A given decrease in the number of matches is a smaller proportional reduction for people with many contacts, thus increases the fraction of infected in the pool. The greater disease risk further decreases contact-seeking and payoffs. Abstinence education has the same effect on sexually transmitted diseases as promoting social distancing on Covid-19 and for the same reason.