Statistical Methods of Causal Effects in Social Sciences
People before stuck to the apparent relation between objects to infer the causal effects.After applying the manipulation and control means to research,they have made great progress but also faced more difficulties.In 1970s,Rubin pointed out that the nature of the causal effects is the issue of counter fact and that some statistical methods used to guarantee the confounding variables is independent from subject assignment.Now,these methods are extensively used to analyze the observable data.The present paper introduces three statistical methods for causal effects inference and explains how to apply the propensity score to data analysis.