Supersize me: How Oversized Coalitions Benefit Junior Coalition Partners

Oversized coalition governments – coalitions including parties not necessarily required in order to secure the support of a parliamentary majority – seem to contradict basic notions of rational choice, such as the desire to maximize office gains. However, historically this type of cabinets has been almost as prevalent in the democratic world as minimal-winning coalitions, and in some countries, such as Finland, Switzerland and Israel it is indeed the norm in government formation. Throughout the years, several explanations of this seeming deviation have been put forth, addressing such interests of the formateur such as curtailing junior partner’s veto powers, keeping potential electoral competitors in check, etc. However, to date there has been almost no focus on how interests of the junior partners are served in oversized coalitions, compared to minimal winning ones. This Paper strives to fill this lacuna. Engaging literature on government maintenance, veto players and party discipline enforcement, I suggest a model in which parties with divergent preferences will opt for an oversized coalition as an arrangement that eases the intra- party tensions between cabinet members and backbenchers. This way, party can “have the cake and eat it”, both enjoying cabinet membership and having the option of breaking from coalition discipline occasionally. After delineating the model and how the hypotheses drawn from it differ than those of previously suggested explanations, I test the model by analyzing government formations and plenary voting patterns in the Israeli parliament between 2003 and 2014, using a dataset containing over 16,000 votes from 10 coalition governments of all types.