“…Starting from the pioneering work of Sager and Thisted (1982), there is now a large literature on modal regression. There are two major approaches to estimating the conditional mode comparable to our method; one is linear modal regression where the conditional mode is assumed to be linear in covariates (Lee, 1989(Lee, , 1993Kemp and Santos-Silva, 2012;Yao and Li, 2014), and the other is nonparametric estimation (Yao et al, 2012;Chen et al, 2016); see also Lee and Kim (1998); Manski (1991); Einbeck and Tutz (2006); Sasaki et al (2016); Ho et al (2017); Khardani and Yao (2017); Krief (2017) for alternative methods including semiparametric and Bayesian estimation. Lee (1989Lee ( , 1993 assume symmetry of the error distribution to derive limit theorems for their proposed estimators, but the symmetry assumption implies that the conditional mean, median, and mode coincide, thereby significantly reducing the complexity of estimating the conditional mode.…”