手法を比較

	Probabilistic Voting Model	Meltzer-Richard Model
分野	Political Economy	Political Economy
系統	MCDM	MCDM
提唱年	1987	1981
提唱者	Assar Lindbeck, Jörgen Weibull & Peter Coughlin	Allan Meltzer & Scott Richard
種類	Formal model of electoral competition	Formal model of redistribution and government size
原典	Lindbeck, A., & Weibull, J. W. (1987). Balanced-budget redistribution as the outcome of political competition. Public Choice, 52(3), 273-297.	Meltzer, A. H., & Richard, S. F. (1981). A Rational Theory of the Size of Government. Journal of Political Economy, 89(5), 914-927.
別名	Probabilistic Voting Theory, Lindbeck-Weibull Model, Coughlin Probabilistic Voting Model, Stochastic Voting Model	Meltzer-Richard Hypothesis, Rational Theory of Government Size, Median Voter Theory of Redistribution, MR Model
関連	4	4
概要	The probabilistic voting model is a formal theory of electoral competition in which each voter's choice between two parties is treated as stochastic rather than deterministic, governed by a smooth probability that depends on the policy utilities the parties offer plus idiosyncratic and partisan preference shocks. Developed by Assar Lindbeck and Jörgen Weibull in 1987 and given its general treatment by Peter Coughlin in 1992, the model replaces the knife-edge switching of the median voter framework with continuous vote-share functions. Two office-seeking parties maximize expected vote share, and the resulting equilibrium maximizes a density-weighted social welfare function in which the most responsive — the swing — voters carry the greatest weight. Crucially, the model delivers a determinate, interior equilibrium even in multidimensional policy spaces where a Condorcet winner generically fails to exist.	The Meltzer-Richard model is the canonical political-economy theory of the size of government, developed by Allan Meltzer and Scott Richard in 1981. It embeds the median voter theorem in a fiscal setting: the decisive median voter chooses a single linear (proportional) income tax rate whose revenue funds a uniform lump-sum transfer to everyone. Because income distributions are right-skewed, the median income falls below the mean, so the median voter is a net beneficiary of redistribution and votes for a positive tax. The model's central prediction is that the size of government rises with the ratio of mean to median income — and therefore with inequality — and with any extension of the franchise that lowers the decisive voter's relative income.