pppFive years after Ronald Ross discovered the link between malaria and mosquitos, American entomologist Leland Howard wrote of the mosquito evil that occurs when everybody's business is nobody's business. Howard's insight was largely ignored, but it captures what social scientists now refer to as the problem of collective action. ppWhen this problem persists in the context of malaria, individuals under-provide prevention and suffer from a higher prevalence of malaria. Imagine a group of people trying to drain a pond where mosquitoes breed. Everyone in the group faces an incentive to free ride, which can hinder their drainage efforts. Thus, when people fail to resolve issues related to collective action, they submit to the mosquito evil and, potentially, to malaria. pp ppThis book explores Howard's logic, the economics of collective action, and the history, epidemiology, and public health of malaria to analyze the conditions under which people privately resolve collective action proble