The effects of alternative power-sharing arrangements: Do “moderating” institutions moderate party strategies and government policy outputs?

Abstract

Advocates of consensual political institutions, i.e. institutions that promote compromise and powersharing among political parties, claim that these institutions promote moderation in government policy outputs. To date, however, there exists little research – either theoretical or empirical – that evaluates whether consensual institutions promote moderation in parties' policy declarations. We develop a multiparty spatial model with policy-seeking parties operating under proportional representation, in which we vary the extent to which government policies reflect power-sharing among all parties as opposed to being determined by a single party. We determine parties' optimal (Nash equilibrium) policy positions and conclude that power-sharing does not typically motivate parties to moderate their policy declarations; in fact, policy positioning under power-sharing appears to be similar to or more extreme than under single-party dominance. Consistent with previous research, however, we find that power-sharing does promote moderation in government policy outputs. Our results have implications for parties’ election strategies, for the design of political institutions, and for representative government.