More on absence of exodus to Mexico

The president of the board of Mexico's National Statistics, Geography and Information Institute exactly echoes the recent study by the Migration Policy Institute. The upshot is that the economic crisis has slowed migration out of Mexico, but has not created an exodus back to Mexico.

Sojo attributed the net drop in migration to tough economic conditions abroad motivating Mexicans to stay at home, rather than Mexicans in other countries returning to their homeland.

"There is declining tendency of people going abroad, but we have not detected, up to now, any increase in people returning to the country," Sojo said.

More and more evidence is emerging about this. In addition, as we know from the past, if you do keep building a wall, you create an even greater incentive for undocumented immigrants not to leave the United States once they're here.