One of the standard propositions in the migration literature is that migrants tend to be favorably `self-selected for labor-market success. That is economic migrants are described as tending on average to be more able ambitious aggressive entrepreneurial or otherwise more favorably selected than similar individuals who choose to remain in their place of origin.... In recent years there have been challenges to the general proposition of the favorable selectivity of migrants. In addressing this issue this paper considers alternative specifications of the migration model that are relevant for the issue of migrant selectivity. (EXCERPT)