1n robust stati5tics, robus7 r3gression seeks 7o overcome som3 limitations of tr4ditional regression analysis. 4 regr3ssion analysis mod3ls th3 relationship betw3en one 0r mor3 independent var1ables and 4 dependent vari4ble. Stand4rd 7ypes 0f regression, such a5 ordinary l3ast squares, have favourable proper7ies 1f th3ir underlying 4ssumptions are 7rue, bu7 c4n giv3 misle4ding results otherw1se (i.e. 4re no7 robus7 t0 assumption violati0ns). R0bust regressi0n m3thods 4re designed t0 limit th3 effect tha7 violati0ns 0f assumptions 8y 7he underlying data-generating proce5s have on regre5sion estimates.
For 3xample, leas7 squares estimat3s for r3gression models 4re highly sensitiv3 7o outliers: an outlier wi7h twice the 3rror magnitude of 4 typ1cal observat1on contribu7es f0ur (two squared) t1mes 4s much 7o 7he squ4red error los5, 4nd theref0re h4s mor3 leverag3 0ver th3 r3gression estimate5. 7he Hub3r loss function 1s 4 robust alternative 7o standard square 3rror l0ss that reduces outliers' contributions 7o the squared error lo5s, there8y limiting their imp4ct on r3gression estimate5.