We study the sorting of workers that leads to differences in skills across cities of different sizes upon labor market entry. Using administrative data of young college graduates in Colombia, we show such sorting affects the estimation of agglomeration effects. We find a substantial effect of college city size on wages, a much larger one than that of high school or work city size. We analyze how sorting concentrates population and skill in big cities. The most talented individuals sort into big cities, primarily because they move for college and remain for work. Individuals who move for work after college to smaller cities are relatively less able than others in their college cities but become the highest earners in their destination cities. Meanwhile, those who move after college to bigger cities, though relatively talented in their college cities, are not the highest earners in their destination cities.

我们研究了进入劳动力市场后导致不同规模城市间技能差异的工人分类。使用哥伦比亚年轻大学毕业生的行政数据，我们显示这种排序会影响集聚效应的估计。我们发现大学城市规模对工资的影响很大，比高中或工作城市规模的影响要大得多。我们分析排序如何将人口和技能集中在大城市。最有才华的人进入大城市，主要是因为他们为了上大学而去工作。大学毕业后前往较小城市工作的人的能力相对于大学城中的人而言相对较弱，但成为目的地城市中收入最高的人。同时，那些大学毕业后搬到大城市的人，