本文采用了1979年11月1979年11月和1989年11月的独特现行人口调查数据，比较了几代墨西哥原产人的工资结构。I find that the sizable earnings advantage U.S.-born Mexican Americans enjoy over Mexican immigrants arises not just from intergenerational improvements in years of schooling and English proficiency, but also from increased returns to human capital for Mexican-origin workers who were born and educated in the United States. Even if we consider immigrants who have worked in the United States for 40 years and who therefore have had ample time for labor market assimilation, my estimates indicate that a discrete jump in earnings and the wage structure occurs between the first and second generations. Progress seems to stall after the second generation, however, as the much more modest gains in schooling and English fluency that occur between the second and third generations do not appear to raise the earnings of Mexican Americans any further.