bias in the sandwich estimator. He also recommended inflating the sandwich estimator by adding a scaled version of the sandwich estimator trace to itself. This concept is unalike those previously proposed in that it applies the adjustment to the entire sandwich estimator. Whereas most adjustments took place inside the calculation of the covariance of the sandwich estimator, this one was applied outside of the summation and not to the individual residuals. Morel’s version of the sandwich estimator, adjusted with the trace, is referred to as VM _ T.
