Classical analysis of health insurance markets often focuses on adverse selection, which creates a direct externality between the enrollees of the same health plan: under an imperfect risk adjustment, the higher the risks of my co-enrollees, the higher my cost of insurance. This has lead to the...

We study competition in two sided markets with common network externality rather than with the standard inter-group e¤ects. This type of externality occurs when both groups benefit, possibly with different intensities, from an increase in the size of one group and from a decrease in the size of...

This paper examines the evolution of drug use in Colombia over the past years. Our analysis, based on surveys from the Dirección Nacional de Estupefacientes, shows that drug consumption grew substantially between 1996 and 2013. The growth occurred for both genders, all ages, socioeconomic...