Table 1.

Quasi-Experimental Methods for Inferring Causality in Nonexperimental Settings

Method	Brief description
Propensity score analysis	Compare individuals who were selected to treatment to statistically similar controls using a matching algorithm
Simultaneous equation models	Using “instruments” (exogenous sources of variable that do not correlate with the error term) to purge the endogenous × variable from the bias
Regression discontinuity	Select individuals to treatment using a modeled cutoff
Difference-in-differences models	Compare a group who receive an exogenous treatment to a similar control group over time
Heckman selection models	Predict selection to treatment (where treatment is endogenous) and then control for unmodeled selection to treatment in predicting y

Note: Taken from Antonakis and colleagues (2010), for further explanations regarding the summed methods we refer to the original article.