手法を比較

	パイロット自然実験	自然実験
分野	実験計画法	実験計画法
系統	Process / pipeline	Process / pipeline
提唱年	2000s–2010s (as formalized practice)	1990s (formal methodological articulation); earlier in epidemiology (John Snow, 1854)
提唱者	Combination of natural experiment tradition (Dunning, Angrist, Pischke) and pilot study methodology	Varied; systematized in econometrics and political science (e.g., Meyer 1995; Angrist & Krueger 1991)
種類	Quasi-experimental feasibility design	Quasi-experimental research design
原典	Dunning, T. (2012). Natural Experiments in the Social Sciences: A Design-Based Approach. Cambridge University Press. ISBN: 9781107017412	Meyer, B. D. (1995). Natural and quasi-experiments in economics. Journal of Business and Economic Statistics, 13(2), 151–161.
別名	feasibility natural experiment, preliminary natural experiment, pilot quasi-experiment, exploratory natural experiment	natural quasi-experiment, naturally occurring experiment, exogenous shock design, as-if randomization
関連	4	3
概要	A pilot natural experiment is a small-scale preliminary study that exploits an existing exogenous event or policy variation to test whether a full natural experiment is viable. It preserves the core logic of natural experiments — using real-world discontinuities to approximate causal inference — while explicitly scoping the work to assess data availability, group comparability, effect detectability, and procedural feasibility before committing resources to a larger study.	A natural experiment exploits a real-world event, policy, or circumstance that assigns individuals to treatment and control conditions in a way that is plausibly random — or at least exogenous to the outcome of interest. Because the researcher does not control assignment, it occupies a middle ground between a true randomized controlled trial and purely observational research, offering stronger causal leverage than conventional observational designs when the as-if randomization assumption holds.