Estimating the Variance of Wages in the Presence of Selection and Unobserved Heterogeneity
识别不同教育水平的潜在工资分布，发现教育自选择导致观测到的组内工资方差偏低，而大学教育与更高工资不平等的关系源于未观测异质性而非不确定性。
Identification of potential wage distributions by education is important to the study of the causal links between education, inequality, and uncertainty. Potential wage inequality within an educational group (that is, the variance in wages if all workers had the same education) exceeds the observed statistics because self-selected education truncates wage distributions. Decomposing potential wage inequality into heterogeneity (known to the agent making the educational choice) and uncertainty (unknown to the agent) suggests that wage uncertainty does not necessarily rise with education. It is unobserved heterogeneity, not uncertainty, that explains the observed relationship between college graduation and higher wage inequality. Copyright by the President and Fellows of Harvard College and the Massachusetts Institute of Technology.