Using comparable micro-level data from three countries, we ask what type of person works in the informal sector and whether informal workers earn lower wages than observationally equivalent workers in the formal sector. The characteristics of informal workers are similar across countries. Surprisingly, when we control for these personal characteristics, we find a significant wage premium associated with formal employment in El Salvador and Peru but a premium associated with work in the informal sector in Mexico. A model of endogenous selection offers little help in explaining the differences in wage patterns. The research casts doubt on the received wisdom that the informal sector, always and everywhere, is a poorly-paid but easily-entered refuge for those who have no other employment opportunities.