השוואת שיטות

	מבחן פלצבו להערכת מדיניות	שיטת המשתנים המתערבים (IV) להסקה סיבתית
תחום	הסקה סיבתית	כלכלת בריאות
משפחה	Regression model	Process / pipeline
שנת המקור	1990s–2000s	1990s (modern applications)
הוגה השיטה	Bertrand, Duflo & Mullainathan (2004 canonical formalization); Imbens & Wooldridge (2009 textbook treatment)	Angrist & Pischke (applied econometrics); rooted in econometric theory
סוג	Falsification / specification check	Method
מקור מכונן	Imbens, G. W., & Wooldridge, J. M. (2009). Recent Developments in the Econometrics of Program Evaluation. Journal of Economic Literature, 47(1), 5-86.	Angrist, J. D., & Pischke, J. S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton: Princeton University Press.
כינויים	placebo test, falsification test, fake treatment test, placebo regression	IV, two-stage least squares, TSLS, causal estimation
קשורות	4	3
תקציר	A policy evaluation placebo test is a falsification check used in quasi-experimental research to validate a causal identification strategy. The researcher applies the same estimation method to a pseudo-treatment — a time period, group, or outcome where the real policy could not have had an effect — and checks that no spurious effect is detected. A null placebo result builds confidence that the main estimate reflects a genuine causal impact rather than bias or confounding.	Instrumental variables (IV) is an econometric method to estimate causal effects when treatment or exposure is not randomly assigned and confounding is severe or unmeasured. IV relies on a third variable (instrument) that influences treatment but does not directly affect the outcome, allowing researchers to isolate the causal effect from the noise of confounding. Developed extensively in econometrics (Angrist & Pischke, 1990s–2000s), IV methods are increasingly used in health economics and health services research to leverage natural experiments and policy changes.