Ministerial Weights and Government Formation: Estimation using a Bargaining Model

This paper proposes a method to estimate relative ministerial weights in parliamentary democracies. Specifically, we combine a bargaining model of government formation with maximum likelihood estimation. The data required for estimation are (i) who the formateurs are, (ii) what each party's voting weight is, and (iii) what ministerial seats each party obtains. We use the variation of the data and the structure of the bargaining model to recover ministerial weights and other parameters. Additionally, the method can measure the effects of voting weights and formateur advantage. We apply our proposed method to the case of Japan. Our results show that political players value pork-related posts (such as the Minister of Construction) more than prestigious ones (such as the Minister of Foreign Affairs). We also find that there is a significant formateur advantage, while voting weights do not have a significant scale effect.