Assimilation, Changes in Cohort Quality, and the Earnings of Immigrants
利用1970和1980年美国人口普查数据，发现移民收入随同化而增长的速度远低于横截面研究预测，这支持了美国移民质量长期下降的假说。
This paper reexamines the empirical basis for two "facts" that seem to be found in most cross-section studies of immigrant earnings: (1) the earnings of immigrants grow rapidly as they assimilate into the United States; and (2) this rapid growth leads to many immigrants' overtaking the earnings of the natives within 10-15 years after immigration. Using the 1970 and 1980 U.S. censuses, this paper studies the earnings growth experienced by specific immigrant cohorts during the period 1970-80. It is found that within-cohort growth is significantly smaller than the growth predicted by cross-section regressions for most immigrant groups. This differential is consistent with the hypothesis that there has been a secular decline in the "quality" of immigrants admitted to the United States.