of single-index models

USA For the class of single-index models, I construct a semiparametric estimator of coefficients up to a multiplicative constant that exhibits l/x- n consistency and asymptotic normality. This class of models includes censored and truncated Tobit models, binary choice models, and duration models with unobserved individual heterogeneity and random censoring. I also investigate a weighting scheme that achieves the semiparametric efficiency bound. 1