Institutions, rules, and equilibria : a unified theory

We propose a new framework to unify three conceptions of institutions that play a prominent role in the philosophical and scientific literature: the equilibria account, the regulative rules account, and the constitutive rules account. We argue that equilibrium-based and rule-based accounts are individually inadequate, but that jointly they provide a satisfactory conception of institutions as rules-in-equilibrium. In the second part of the paper we show that constitutive rules can be derived from regulative rules via the introduction of theoretical terms. We argue that the constitutive rules theory is reducible to the rules-in equilibrium theory, and that it accounts for the way in which we assign names to social institutions.