Modelling Coalitions that Cannot Coalesce: A Critique of the Laver-Shepsle Approach

Abstract

The Laver and Shepsle (LS) model assumes that coalition government partners can never co‐operate to agree policy jointly, but must allocate ministerial portfolios between them, with each side's ministers acting as partisan ‘barons ‘ in their departments. Portfolio allocations do indeed make some initial difference as a stage through which all coalition negotiations must pass. But in the LS pure model their empirical significance for a coalition's eventual policy stance is greatly exaggerated, ignoring the importance of a range of governance mechanisms in fostering policy coalescence. Theoretically, we should also expect two rational parties always to offer policy stance concessions in bargaining, which move away from the LS ‘lattice points’, in many circumstances maximising their joint welfare. Pressure from voters, activists, party backers and the media will be for a coalition deal more comprehensible than the lattice points for non‐elite audiences, located somewhere along the contract line from party A'...