Regression transformation diagnostics in transform-both-sides model

We present two methods for regression transformation diagnostics in the transform-both-sides model (see Carrol and Ruppert, 1984, 1987; Hinkley and Wang, 1988). One is based on the likelihood displacement proposed by Cook and Weisberg (1982) for assessing the influence of individual cases on the maximum likelihood estimator of a transformation parameter; the other is based on the local influence proposed by Cook (1986) for assessing the influence of small perturbations on the transformation parameter estimator.