The Mafia is often cited as one of the main reasons why Sicily has lagged behind the rest of Italy in economic and social development. This column describes how in an environment with weak state presence, the socialist threat of Peasant Fasci organisations at the end of the 19th century induced landholders, estate managers, and local politicians in Sicily to turn to the Mafia to resist and combat peasant demands. Within a few decades, the presence of the Mafia appears to have significantly reduced literacy, increased infant mortality, limited the provision of a variety of local public goods, and may also have significantly reduced local political competition.