Parliamentary institutions and portfolio allocation in coalition governments

How does variation in the involvement of legislators in the making and breaking of governments affects the share of portfolios that formateur parties reap? Legislative bargaining models typically predict over-compensation of formateur parties in coalition cabinets, yet allocations tend to be highly proportional. We argue that restrictive rules for government formation and termination increase the prospects of coalition durability and provide formateur parties with weaker incentives to overcompensate coalition partners in exchange for their support. Analysing data on 583 coalition governments in 30 parliamentary democracies over 1945–2015, we find that absolute majority requirements for cabinet formation and removal tend to advantage formateur parties in portfolio allocation. These findings are robust to various coalition characteristics and national settings. Moreover, we improve the measurement of portfolio allocation by basing calculations on the Sainte-Lagüe divisor method, removing cabinet-size bias, and providing a substantially meaningful measure of under- and overrepresentation of parties in coalition governments.