Majority Rule and Coalitional Stability

In this note we study the centralization vs. decentralization issue for the management of a given collective activity. The aim is to characterize a class of decision rules that guarantees the stability of global cooperation (i.e centralization) against the incentive of coalitions of citizens to opt-out, towards forms of decentralized organizations. We show that a simple majority rule required to break global cooperation guarantees the existence of core-stable allocations, independently of the expected behaviour of individuals in the minority. We also show that if majorities can extract resources from minorities, stability may require a supermajority rule, whose threshold is increasing in its extraction power.