Angrist, J D; Imbens, G W; Krueger, A B - In: Journal of Applied Econometrics 14 (1999) 1, pp. 57-67
Two-stage-least-squares (2SLS) estimates are biased towards the probability limit of OLS estimates. This bias grows with the degree of over-identification and can generate highly misleading results. In this paper we propose two simple alternatives to 2SLS and...