手法を比較

	Coalition Formation Analysis	Veto Player Analysis
分野	Political Economy	Political Science
系統	MCDM	MCDM
提唱年	1962	1995
提唱者	William Riker; Michael Laver & Norman Schofield	George Tsebelis
種類	Formal theory of coalition selection	Comparative institutional analysis framework
原典	Riker, W. H. (1962). The Theory of Political Coalitions. Yale University Press. ISBN: 9780300001754	Tsebelis, G. (2002). Veto Players: How Political Institutions Work. Princeton University Press. ISBN: 9780691091891
別名	Minimal Winning Coalition Theory, Riker Size Principle, Coalition Theory, Government Coalition Analysis	Veto Players Theory, Veto Points Analysis, Tsebelis Veto Player Framework, Policy Stability Analysis
関連	4	4
概要	Coalition formation analysis is the formal study of which subset of parties will combine to form a governing or decision-making coalition when no single party commands a majority. William Riker's 1962 The Theory of Political Coalitions supplied the foundational logic: under pure office-seeking, rational politicians form minimal winning coalitions and, by the size principle, the smallest winning coalition possible, so that the spoils of office are divided among as few partners as necessary. Michael Laver and Norman Schofield's 1990 Multiparty Government enriched this with policy-seeking motives, showing that coalitions also tend to be ideologically connected. The framework predicts coalition membership from seat shares and party positions.	Veto player analysis is a spatial-institutional framework, developed by George Tsebelis in his 1995 article and 2002 book, for predicting the capacity of a political system to change policy. A veto player is any individual or collective actor whose agreement is required to alter the status quo. The theory shows that the potential for policy change shrinks as the number of veto players grows, as the ideological distance between them widens, and as their internal cohesion increases — three structural variables that together determine a system's policy stability independently of constitutional labels such as presidentialism or parliamentarism.