Separation of Powers and Accountability: Towards a Formal Approach to Comparative Politics

A political constitution is like an incomplete contract: it spells out a procedure for making decisions and for delegating power, without specifying the contents of those decisions. This creates a problem: the appointed policymaker could use this power for his own benefit against the interests of the citizens. In democracies, elections are the primary mechanism for disciplining public officials. But elections are not sufficient. Separation of powers between executive and legislative bodies also helps the voters, in two distinct ways. First, it can elicit information held by the appointed officials and not otherwise available to the voters. Second, by playing one body against the other and by aligning the interest of the weaker body with their own, the voters can induce the two bodies to discipline each other. Separation of power only works to the voters' advantage if it is appropriately designed, however, and it can be detrimental if it creates a ''common pool'' problem. These advantages of separation of powers are present both in Presidential and in Parliamentary democracies. Government appointment rules in Parliamentary democracies must be appropriately designed, however, to prevent collusion.