Leverage, local influence and curvature in nonlinear regression

Abstract

SUMMARY The connections between measures of leverage, statistical curvature, and the local influence of a mean-shift perturbation are explored in nonlinear regression models. The circumstances under which the Jacobian leverage reduces to a commonly-used linear approximation are found to be connected to the effective residual curvature of the nonlinear model. The local influence of a mean-shift perturbation in the model function is seen to be closely related to the Jacobian leverage.