Abstract
We obtain Bahadur-type representations for one-stepL-estimators,M- and one-stepM-estimators in the linear model. The order of the remainder terms in these representations depends on the smooth-ness of the weight function forL-estimators and on the smoothness of the ψ-function forM- and one-stepM-estimators. We use the representations to investigate the asymptotic relations between these estimators. In particular, we show that asymptotically equivalentL- andM-estimators of the slope parameter exist even when the underlying distribution is asymmetric. It is important to consider the asymmetric case for both practical and robustness reasons: first, there is no compelling argument which precludes asymmetric distributions from arising in practice, and, secondly, even if a symmetric model can be posited, it is important to allow for the possibility of mild (and therefore difficult to detect) departures from the symmetric model.
Similar content being viewed by others
References
Bickel, P. J. (1973). On some analogues to linear combinations of order statistics in the linear model,Ann. Statist.,1, 597–616.
Bickel, P. J. (1975). One-step Huber estimates in the linear model,J. Amer. Statist. Assoc.,70, 428–433.
Huber, P. J. (1973). Robust regression: Asymptotics, conjectures and Monte Carlo,Ann. Statist.,1, 799–821.
Jaeckel, L. A. (1971). Robust estimates of location: Symmetry and asymmetric contamination,Ann. Math. Statist.,42, 1020–1034.
Jurečková, J. (1977). Asymptotic relations ofM-estimates andR-estimates in linear regression model,Ann. Statist.,5, 464–472.
Jurečková, J. (1983a). Robust estimators of location and regression parameters and their second order asymptotic relations,Proc. 9th Prague Conf. on Inform. Theory, Random Processes and Statist. Decision Function, (ed. J. A. Višek), 19–32, Reidel, Dordrecht.
Jurečková, J. (1983b). Winsorised least squares estimator and itsM-estimator counterpart,Contributions to Statistics: Essays in honour of Norman L. Johnson, (ed. P. K. Sen), 237–245, North Holland, Amsterdam.
Jurečková, J. (1983c). Trimmed polynomial regression,Comment. Math. Univ. Carolin.,24, 597–607.
Jurečková, J. (1984). Regression quantiles and trimmed least squares estimator under a general design,Kybernetika (Prague),20, 345–357.
Jurečková, J. (1986). Asymptotic representations ofL-estimators and their relations toM-estimators,Sequential Anal.,5, 317–338.
Jurečková, J. and Portnoy, S. (1987). Asymptotics for one-stepM-estimators in regression with application to combining efficiency and high breakdown point,Comm. Statist. A—Theory Methods,16, 2187–2199.
Jurečková, J. and Sen, P. K. (1984). On adaptive scale-equivariantM-estimators in linear models,Statist. Decisions,2 (Suppl. Issue No. 1), 31–46.
Jurečková, J. and Sen, P. K. (1989). Uniform second order asymptotic linearity ofM-statistics in linear models,Statist. Decisions,7, 263–276.
Koenker, R. and Bassett, G. (1978). Regression quantiles,Econometrica,46, 33–50.
Koenker, R. and Portnoy, S. (1987).L-estimation for linear models,J. Amer. Statist. Assoc.,82, 851–857.
Koul, H. L. (1969). Asymptotic behavior of Wilcoxon type confidence regions,Ann. Math. Statist.,40, 1950–1979.
Ortega, J. M. and Rheinboldt, W. C. (1973).Iterative Solution of Nonlinear Equations in Several Variables, Academic Press, New York.
Relles, D. (1968). Robust regression by modified least squares, Ph. D. Thesis, Yale University.
Rivest, L. P. (1982). Some asymptotic distributions in the location-scale model,Ann. Inst. Statist. Math.,34, 225–239.
Ruppert, D. and Carroll, R. J. (1980). Trimmed least squares estimation in the linear model,J. Amer. Statist. Assoc.,75, 828–838.
van Eeden, C. (1983). On the asymptotic relation betweenL-estimators andM-estimators and their asymptotic efficiency relative to the Cramér-Rao lower bound,Ann. Statist.,11, 674–690.
Welsh, A. H. (1986). Bahadur representations for robust scale estimators based on regression residuals,Ann. Statist.,14, 1246–1251.
Welsh, A. H. (1987a). The trimmed mean in the linear model (with discussion),Ann. Statist.,15, 20–36 (correction:ibid. Welsh, A. H. (1988). The trimmed mean in the linear model (with discussion),Ann. Statist. 16, 480).
Welsh, A. H. (1987b). One-stepL-estimators for the linear model,Ann. Statist.,15, 626–641 (correction:ibid. Welsh, A. H. (1988). One-stepL-estimators for the linear model,Ann. Statist.,16, 481).
Welsh, A. H. (1987c). Kernel estimates of the sparsity function,Statistical Data Analysis Based on the L 1 -norm and Related Methods, (ed. Y. Dodge), 369–378, Elsevier Science Publishers B. V., Amsterdam.
Yohai, V. J. and Maronna, R. A. (1979). Asymptotic behaviour ofM-estimators for the linear model,Ann. Statist.,7, 258–268.
Author information
Authors and Affiliations
About this article
Cite this article
Jurečková, J., Welsh, A.H. Asymptotic relations betweenL- andM-estimators in the linear model. Ann Inst Stat Math 42, 671–698 (1990). https://doi.org/10.1007/BF02481144
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02481144