Job Discrimination, Market Forces, and the Invisibility Hypothesis
提出“不可见性假说”，认为弱势工人的技能不易被新雇主发现，而晋升能提高其可见性。在竞争性劳动力市场均衡中，企业通过将弱势工人隐藏于低层岗位获利，导致其工资和晋升机会低于同等条件的其他工人，人力资本投资回报也更低。
The Invisibility Hypothesis holds that the job skills of disadvantaged workers are not easily discovered by potential new employers, but that promotion enhances visibility and alleviates this problem. Then, at a competitive labor market equilibrium, firms profit by hiding talented disadvantaged workers in low-level jobs. Consequently, those workers are paid less on average and promoted less often than others with the same education and ability. As a result of the inefficient and discriminatory wage and promotion policies, disadvantaged workers experience lower returns to investments in human capital than other workers.