The logic of Gamson's Law

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Political parties, when forming coalition governments, are greatly concerned with the allocation of cabinet portfolios: how many (and which) posts will each party get? In the extensive literature on this issue, the most prominent landmark is Gamson's Law. Gamson (1961, 376) argued that parties seeking to form a coalition government would each demand a share of portfolios proportional to the amount of resources-specifically, seats in the assembly-that each contributed to the coalition. Early work strongly supported a modified version of this hypothesis. Indeed, as noted by numerous scholars, Gamson's Law is "one of the [statistically most successful generalizations] in political science." Its statistical success notwithstanding, Gamson's Law has been appropriately challenged on theoretical grounds. The argument in its favor is terse to the point of being a one-liner. Moreover, it is in tension with standard bargaining theories in which a party's ability to pivot between alternative minimal winning coalitions and/or its ability (as "formateur") to propose governments determine its portfolio payoff. Gamson's Law has been viewed as suffering from a "critical weakness," in that "it focuses on the effects of seats shares [when] the theoretically relevant concept is shares of voting weights" (italics in original). In this proposal, the investigators offer a new explanation of Gamson's Law. They argue that governments do not always form in an unconstrained bargaining environment, in which all parties are free to pivot between alternative majorities at will. In particular, they are sometimes constrained by pre-election pacts that publicly commit them to enter government with stipulated partners. They argue that the signatories to such pacts will need to negotiate, prior to the election, a principle that will guide the allocation of cabinet posts after the election (should the coalition succeed in getting into government); and that the most natural principle from a pre-election viewpoint is Gamsonian-largely because such a principle gives all parties in the coalition a strong incentive to work hard to provide the public good of a coalition majority (rather than free riding). Broader Impact: The research effort will be publicized on an existing web site, www.settingtheagenda.com. The investigators hope to enhance the infrastructure for comparative legislative research, by making public data, codebooks, and analytical files for academic, research and non-commercial purposes; and by continuing to foster the network of scholars and students with whom they collaborate. They also hope that a better understanding of how legislatures work, in places where democracy thrives, may contribute to strengthening legislative institutions in places where democracy struggles to establish itself.