Robust tests of inequality constraints and one-sided hypotheses in the linear model

Abstract

SUMMARY For the linear regression model with independent and identically distributed errors, robust tests of various hypotheses on the regression parameter are developed; by ‘robust’, we mean robustness of size and power against long-tailed error distributions which may not be symmetric. The proposed test statistic, denoted by F M , resembles the usual F -statistic. The two main results are (i) under the null hypothesis, the asymptotic distribution of F M and that of the least squares based F -statistic are the same; and (ii) the Pitman asymptotic efficiency of F M relative to F is equal to the asymptotic efficiency of the corresponding M -estimator relative to the least squares estimator. An example and simulation results illustrate that F M has desirable robustness properties compared to F