This article seeks to explain the contradiction between the promises of welfare gains derived from the economic models recommending the removal of immigration restrictions and the realities experienced by countries attempting to apply restrictions to immigration flows. A formal model is built in...

[Introduction:] Whatever workers may take with them when they migrate, they cannot possibly transfer their home country's information structure. Consequently, foreign-country employers are not as well informed about home-country workers as are home-country employers. Typically, migration runs...