This paper considers the estimation of the random coefficient dummy endogen
ous variable model under a symmetry and index condition for the error distr
ibution. We follow a two-step approach. The selection equation is estimated
first; in the second step an instrumental variables estimator is proposed
for the ourcome equation through a pairwise comparison method. Our approach
can be readily extended to the general switching regression model. In cons
trast to the existing literature on sample selection models, the exclusion
restriction is not needed here for model identification; furthermore, the i
ntercept term for the outcome equation can be estimated at the usual parame
tric rate. (C) 1999 Elsevier Science S.A. All rights reserved. JEL classifi
cation: C31; C34.