The mafia is a set of firms sharing a protected trademark

Evidence

In conclusion, we can define the mafia as that set of firms which (1) are active in the protection industry under a common trademark with recognizable features; (2) acknowledge one another as the legitimate suppliers of authentic mafioso protection; and (3) succeed in preventing the unauthorized use of their trademark by pirate firms. — Diego Gambetta, The Sicilian Mafia The Business of…, 410

Categorization

• DEFINE: Gambetta’s formal definition of the mafia as trademarked protection firms — the definitional core the reader’s whole project rests on.
• XREF: The three-part definition maps exactly onto the reader’s Gamabetta/Milgrom framework: trademark = brand reputation, mutual recognition = private judges validating authenticity, preventing piracy = enforcement of extralegal contractual regime.