Resumen de Common law efficiency when joinder and class actions fail as aggregation devices.

Frank Fagan, Urmee Khan

• We develop a litigant-based model of rule selection where parties choose to litigate rules that are efficient between two parties, but inefficient as between a potential class or potentially joined litigants and a counter-party. Collective action problems lead to incomplete party formation, which generates continuous litigation of seemingly efficient rules. By accounting for externalities borne by non-parties, we show that rules which are allocatively efficient across both parties and non-parties are evolutionary stable for any given judicial ideology or judicial preference for prestige, thus preserving the explanatory power of the Efficiency of Common Law Hypothesis. [ABSTRACT FROM AUTHOR]