Hahn, Jinyong and Hausman, Jerry. 2021. "Problems with the Control Variable Approach in Achieving Unbiased Estimates in Nonlinear Models in the Presence of Many Instruments."
Version
Author's final manuscript
Abstract
Abstract
We present a pseudo-panel model and argue that the control variable approach is subject to the many instrument problem, since it uses the predicted value of the endogenous variable. We show how the bias can be analytically characterized. Finally, we demonstrate the problems of split sample cross fitting.
