Hostile Twins: Rethinking Coalition Governance in Parliamentary Democracies

Multiparty governments are plagued with preference heterogeneity and uncertainty about policy outcomes. Ministers have two principals: their party and the coalition, which creates potential dangers of agency loss. Literature on coalition governance mechanisms identified junior ministers, parliamentary committees, and coalition agreements as privileged arenas to keep tabs on partners. In this paper we argue that parties use jurisdiction overlap to shadow each other at the ministerial level. We define a hostile twin situation when different parties control the portfolios that form a jurisdiction combination. We test this hypothesis for 12 West European parliamentary democracies since 1945. Our contribution conjugates a Monte Carlo simulation, which estimates whether real-world distribution differs significantly from expected random allocation, with indepth interviews with more than forty former ministers. Results show that hostile twins are used extensively as coalition governance mechanisms, particularly because of their capacity to curb information asymmetries and to avoid interministerial gridlock.