A Mean-Variance Portfolio Analysis of the Demand and Supply of a Potentially Infectious Service

A health-risking illegal personal service is transacted when the expected extra satisfaction rate exceeds the ratio of the expected extra cost to the legal service price. Its prevalence decreases with the costs of risk bearing for the providers and clients. Law-enforcement effort lowers (raises) the equilibrium price of the illegal and hazardous service when the ratio of the providers’ and the clients’ degrees of absolute risk aversion is greater (smaller) than the ratio of the law-enforcement elasticities of their cost bearing.