The North American experience with international migration stands in unique contrast to
much of the rest of the world. This paper uses microdata drawn from the national censuses of
Canada, the United States, and Mexico, and applies the same methodological framework to these
data to examine the impact of international migration on the labor market. We find a numerically
comparable and statistically significant inverse relation between immigrant-induced shifts in
labor supply and wages in each of the three countries: A 10 percent labor supply shift is
associated with about a 3 to 4 percent opposite-signed change in wages. Despite the similarity in
the wage elasticity, the impact of international migration on the wage structure differs
significantly across countries. In Canada, international migration substantially narrowed wage
inequality because immigrants in Canada tend to be disproportionately high-skill. In the United
States, international migration substantially increased wage inequality because immigrants in the
United States tend to be disproportionately low-skill. In Mexico, however, emigration rates are
highest in the middle of the skill distribution and lowest at the extremes. As a result, international
migration greatly increased relative wages in the middle of the Mexican skill distribution and
lowered relative wages at the extremes. Paradoxically, the large-scale migration of workers from
Mexico may have reduced slightly the relative wage of the low-skill workers remaining in that
country.