Mexico and Ireland, traditionally countries of emigration, experienced pronounced multinationalization of their economies during the 1990s. In Ireland net emigration declined, but in Mexico it remained quite high, suggesting that Ireland advanced in the mobility transition while Mexico did not. Several reasons are offered to explain this, reflecting Mexico's relationships with the United States, multinational corporations, and local income and social conditions in Mexican regions. In Ireland and its relationship with the United Kingdom, by contrast, these factors generally took the reverse direction. This article uses the comparison to examine the relationship between declining emigration and multinational investment and the question of whether Mexico may be expected eventually to reverse its present trends.