This paper considers the semiparametric estimation of binary choice sample selection models under a joint symmetry assumption. Our approaches overcome various drawbacks associated with existing estimators. In particular, our method provides root-n consistent estimators for both the intercept and...

This paper considers semiparametric estimation of a nonstationary transformation model with panel data. One of the drawbacks of most existing semiparametric procedures is the requirement of stationarity assumption. Under a symmetry condition, a new estimator is proposed, allowing for...