Power enhancement via cross-fit variance estimation: Applications to specification, overidentification, and many-restriction testing
交叉拟合方差估计的功效增强:模型设定、过度识别与多重约束检验
Quadratic-form test statistics are widely used in econometrics, and their performance depends on accurate variance estimation. Conventional plug-in estimators are consistent under the null hypothesis, but under alternatives the drift in the residuals inflates them and the test loses power. We develop a general framework for variance estimation in such statistics, replacing one of the two squared-residual factors by an auxiliary linear combination of the residuals…