Earnings, Education, and Experience
指出，在估计教育回报时，将大学毕业生与研究生合并会高估大学教育的回报，偏差可达12%。
The value of additional education is typically measured by the increase in earnings that results. The largest gains are realized on completion of a degree, whether high school, college, or post-graduate. Failure to correctly specify an empirical earnings function can lead to substantial bias. In this article, the authors show that a common misspecification-combining college graduates with post-graduates-may bias the returns to a college education upward by as much as 12 percent.