手法を比較

	Difference-in-Means Estimator	Field Experiment in Politics
分野	Political Science	Political Science
系統	Process / pipeline	Process / pipeline
提唱年	1923	2000
提唱者	Jerzy Neyman (design-based potential-outcomes framework)	Gerber & Green (modern political field experiments)
種類	Design-based estimator of the average treatment effect	Randomized experiment conducted in a real political setting
原典	Gerber, A. S., & Green, D. P. (2012). Field Experiments: Design, Analysis, and Interpretation. New York: W. W. Norton. ISBN: 9780393979954	Gerber, A. S., & Green, D. P. (2000). The Effects of Canvassing, Telephone Calls, and Direct Mail on Voter Turnout: A Field Experiment. American Political Science Review, 94(3), 653–663.
別名	Neyman estimator, Design-based ATE estimator, Difference of sample means, Mean-difference treatment effect estimator	Political field experiment, Get-out-the-vote experiment, GOTV experiment, Voter mobilization experiment
関連	4	4
概要	The difference-in-means estimator is the design-based workhorse for analyzing randomized experiments: it estimates the average treatment effect simply as the difference between the average outcome among treated units and the average outcome among control units. Rooted in Jerzy Neyman's potential-outcomes framework and central to modern treatments by Imbens and Rubin and by Gerber and Green, it is unbiased under randomization, comes with a conservative Neyman variance estimator, and supports exact randomization inference, requiring no model of how outcomes are generated.	A field experiment in political science randomizes a real intervention — such as a get-out-the-vote canvass, mailing, or phone call — among genuine political actors in their natural environment and compares behavioral outcomes like validated turnout. Revived for the discipline by Gerber and Green's 2000 voter-mobilization study and codified in their 2012 textbook, the approach combines the causal leverage of randomization with the realism of consequential, real-world settings, while carefully distinguishing the effect of being assigned a treatment from the effect of actually receiving it.