 He is best known for developing, with Whitney K. Newey, the Newey–West estimator, which robustly estimates the covariance matrix of a regression model when errors are heteroskedastic and autocorrelated.West lives in Madison, Wisconsin with his wife and two children.A Newey–West estimator is used in statistics and econometrics to provide an estimate of the covariance matrix of the parameters of a regression-type model when this model is applied in situations where the standard assumptions of regression analysis do not apply.