A Distance Covariance-based Estimator
基于距离协方差的估计量
This paper proposes an estimator that relaxes the conventional relevance condition in instrumental variable (IV) analyses. The method allows endogenous covariates to be weakly correlated, uncorrelated, or even mean-independent -- though not independent -- of the instruments, enabling the use of the maximal set of relevant instruments in a given application. Identification is attainable without exclusion restrictions and without finite-moment assumptions on the disturbance…