Signaling and Employer Learning with Instruments
利用挪威不同城市的义务教育法变化构建隐藏和透明工具变量，区分教育的私人回报和社会回报，发现私人回报率为7.9%，其中70%来自生产力提升，30%来自信号传递。
This paper considers the use of instruments to identify and estimate private and social returns to education within a model of employer learning. What an instrument identifies depends on whether it is hidden from, or transparent (i.e., observed ) to, the employers. A hidden instrument identifies private returns to education, and a transparent instrument identifies social returns to education. We use variation in compulsory schooling laws across noncentral and central municipalities in Norway to, respectively, construct hidden and transparent instruments. We estimate a private return of 7.9 percent, of which 70 percent is due to increased productivity and the remaining 30 percent is due to signaling.