Reforms undertaken in Peru in the early 1990s might have resulted in a slight reduction of the informal sector. Costs associated with becoming and staying informal, and benefits of becoming formal might have increased. This, when a legalistic definition of informality is used. Earnings differentials between formal and informal self-employed workers are negligible although they persist between formal and informal salaried workers. Skilled workers are more likely to be found in the formal sector and informal wage earners tend to be younger and less skilled. The earnings generating process for both the formal and the informal self-employed workers is similar.