Constraints on Cabinet Formation in Parliamentary Democracies

Coalition theory typically treats political parties involved in government formation in parliamentary democracies as if they were unconstrained players in an institution-free world. Yet actual coalition options are often severely constrained by institutional arrangements and prior commitments. We develop a systematic account of different constraints on government formation and examine their frequency across 10 parliamentary democracies. Hypothetical and empirical examples demonstrate how a small number of constraints can dramatically reduce the range of coalition options and redistribute bargaining power among political parties. More adequate coalition theories need to recognize the effects of such constraints and to build on the theoretical lessons of the neoinstitutionalist approach to legislative behavior.