Portfolio Importance and the Seat-Payoff Proportionality

The near-perfect relationship between the share of parliamentary seats parties bring to governing coalitions and the proportion of cabinet positions they receive is one of the striking puzzles of coalition research. The lack of a portfolio valuation scheme shared by all parties involved in cabinet bargaining has made it difficult to assess cabinet payoffs not only in terms of the number of portfolios parties receive, but also in terms of their importance. This paper uses the official rankings of ministerial departments in every government of the Fifth French Republic (1958-2014) as cardinal weights to establish an objective importance measure of the share of cabinet positions that parties receive. The results show that the proportionality effect is further strengthened when the portfolio importance measure is used. This case-study emphasizes the kind of country specific data that may be used to devise similar measures of cabinet payoffs in other parliamentary democracies.