Protection demand, not commodity prosperity, predicts mafia entry into a market.

Evidence

When seeking to identify markets which attract mafiosi or foster their autonomy, if we are to remain consistent with our theory we must look first of all at those markets in which the demand for protection is especially pronounced. In doing so we are not necessarily looking for a high level of demand for other commodities. Although active markets sometimes go hand in hand with better opportunities for dealers in protection, there is no theoretical reason why this should always be the case. — Diego Gambetta, The Sicilian Mafia The Business of…, 225

Categorization

• XREF: Directly parallels Milgrom et al.’s law-merchant analysis: demand for third-party enforcement scales with the protection-intensity of a market, not raw wealth. Falsifiable prediction the reader can test against Puzo’s scenes of Bonasera needing protection despite modest means.
• SEED: A reframing angle: ‘the mafia follows protection intensity, not prosperity’ — an article testing which Sicilian markets the state left exposed.