International migration and real wages: is there any neo-classical ambiguity?

"Recent research has shown that while labor emigration increases the nominal wage rate, the impact on the real wage rate remains quite ambiguous. The present paper reexamines the issue under the standard two-factor, two-commodity international trade model normally employed for this purpose. The principal finding of this paper is that once the problem is correctly formulated and analyzed, introducing utility-maximizing consumers, no such ambiguity exists. Indeed, labor emigration always leads to an increase in the welfare (real wage) of labor in the source country."