An article at The Journal of Economic History traces the rise of the Mafia to the production of lemons and oranges in Sicily. While citrus fruits were always popular, their importance was boosted exponentially when they were revealed to be both a preventative and a cure for scurvy, which was a plague among long-distance sailors.
In this article, we argue that the mafia arose as a response to an exogenous shock in the demand for oranges and lemons, following Lind's discovery in the late eighteenth century that citrus fruits cured scurvy. More specifically, we claim that mafia appeared in locations where producers made high profits from citrus production for overseas export. Operating in an environment with a weak rule of law, the mafia protected citrus production from predation and acted as intermediaries between producers and exporters. Using original data from a parliamentary inquiry in 1881–1886 on Sicilian towns, the Damiani Inquiry, we show that mafia presence is strongly related to the production of oranges and lemons. The results hold when different data sources and several controls are employed.
Is this why there are so many oranges in The Godfather? You can read the entire paper here. -via Metafilter