In this case the interests of the protection firm and its customers coincide, for those already paying for protection would prefer that everybody else in the neighborhood pay his share. We arrive at the apparent paradox whereby the standard piece of evidence from which we infer that a dealer is being forced to pay extortion money—for example, a shop window blowing up—might simply mean that he is being punished for free riding at the expense of those around him, who are paying for a commodity from which he benefits without bearing his share of the cost. Forcing people to pay may be analytically equivalent to picketing by a union: there, too, the aim is to make people pay for what they may all eventually get, in this case wage increases.

XREF: Connects to collective action problems and the free-rider problem familiar from Mancur Olson and rational choice theory.

Diego Gambetta, The Sicilian Mafia The Busi…, loc. 79