Berkowitz, Daniel; Caner, Mehmet; Fang, Ying - In: Journal of Econometrics 166 (2012) 2, pp. 255-266
This paper shows how valid inferences can be made when an instrumental variable does not perfectly satisfy the orthogonality condition. When there is a mild violation of the orthogonality condition, the Anderson and Rubin (1949) test is oversized. In order to correct this problem, the...