Abstract
If $M$ is not convex, and the underlying density is multi-modal, $M$-estimators can be inconsistent. Examples are given, as well as some positive results.
Citation
D. A. Freedman. P. Diaconis. "On Inconsistent $M$-Estimators." Ann. Statist. 10 (2) 454 - 461, June, 1982. https://doi.org/10.1214/aos/1176345786
Information