Training and Lifetime Income
质疑在职培训对工人福利的重要性，认为培训可能使终身收入增加不超过1%，并基于非参数方法从工资曲线估计学习技术，比较最优投资与不投资时的终身收入。
This paper challenges the notion that on-the-job training investments are quantitatively important for workers' welfare and argues that on-the-job training may not increase lifetime income by more than 1 percent. I argue that it is very difficult to reconcile the slowdown in wage growth late in a worker's career with optimizing behavior unless the technology for learning on the job is such that it generates very low gains from training. The analysis is based on a nonparametric methodology for estimating the learning technology from wage profiles; the results are arrived at by comparing the lifetime income when the worker optimally invests in his human capital to the one where he does not make any investments.