Minimax Properties of $M-, R-$ and $L$-Estimators of Location in Levy Neighbourhoods
Lévy 邻域中位置参数 M、R 与 L 估计量的极小极大性质
In the context of Huber's theory of robust estimation of a location parameter, the literature on minimax properties of $M$-, $R$- and $L$-estimators is surveyed. New results are obtained for the model in which the unknown error distribution is assumed to lie in a Levy neighbourhood of a symmetric distribution $G: \mathscr{P}_{\varepsilon,\delta}(G) = \{F\mid G(x - \delta) - \varepsilon \leq F(x) \leq G(x + \delta) + \varepsilon \text{for all} x\}$. Under reasonably general…