Constitutional Rules

Preliminary: please do not quote or circulate without the authors’ permission. This paper proposes a normative theory of constitutional rules. We characterize the set of optimal constitutional rules under different assumptions about the degree of contractual imperfections. Our model explains why constitutions contain different types of rules. In particular, we derive conditions under which it is optimal, in addition to a standard decision rule (e.g., simple majority), to introduce veto rules (that block certain types of decisions) and supermajority rules (that allow the veto rule to be overruled). Our model also explains the existence of amendment rules and checks and balances