So sánh phương pháp

	Spatial Voting Model	Voting Power Index Analysis
Lĩnh vực	Political Science	Political Science
Họ	MCDM	MCDM
Năm ra đời	1957	1954
Người khởi xướng	Harold Hotelling, Duncan Black & Anthony Downs	Lloyd Shapley & Martin Shubik; John F. Banzhaf III
Loại	Formal model of electoral and legislative choice	Cooperative game-theoretic measure of a priori voting power
Công trình gốc	Downs, A. (1957). An Economic Theory of Democracy. Harper & Row. ISBN: 9780060417505	Shapley, L. S., & Shubik, M. (1954). A Method for Evaluating the Distribution of Power in a Committee System. American Political Science Review, 48(3), 787-792.
Tên gọi khác	Spatial Theory of Voting, Downsian Model, Proximity Voting Model, Median Voter Model	Voting Power Index, Shapley-Shubik Index, Banzhaf Power Index, A Priori Voting Power Analysis
Liên quan	4	4
Tóm tắt	The spatial voting model represents voters and political alternatives as points in a common geometric policy space and assumes that each voter supports the alternative nearest to their own ideal point. Rooted in Hotelling's location theory, Duncan Black's 1948 single-peakedness result, and Anthony Downs's 1957 economic theory of democracy, the model yields two foundational results: the median voter theorem, which identifies the equilibrium policy in one dimension, and the Downsian prediction that two vote-seeking parties converge toward the center. It is the workhorse formalism behind modern empirical estimation of political positions.	Voting power index analysis measures the a priori capacity of each member of a weighted voting body to influence collective decisions, defined as the probability that the member is pivotal — that their vote turns a losing coalition into a winning one. The two canonical indices are the Shapley-Shubik index, introduced by Lloyd Shapley and Martin Shubik in 1954 as a specialization of the Shapley value to simple voting games, and the Banzhaf index, formalized by John Banzhaf in 1965. Both reveal that a player's share of power generally differs sharply from its share of votes.