Abstract:
In this paper I discuss the specification of self-selection models with random parameters. I demostrate that in a self-selection model, misspecification of the parameter structure as constant causes blased estimates, and the direction of the bias leads to an under-estimation of the selectivity effect. I estimate a self-selection model of moonlighting with random parameters and find that: the selectivity effect, which was almost absent in the constant parameter version of the model, is indeed significant.
