I show that the labor-market crowding out of less-educated workers can be understood as the labor-market response to an adverse-selection problem. When high-skilled workers apply for less skill-intensive jobs, adverse selection arises when employment contracts cannot systematically discriminate against education level, even though overqualified workers are more likely to quit. In order to separate workers, the equilibrium distorts the labor-market outcomes of less-educated workers with an inefficiently high unemployment rate. Furthermore, the distortion creates a market value of post-secondary vocational education, because it acts as an entry barrier and protects less-educated workers from the competition of overqualified college graduates.

我表明劳动力市场对受教育程度较低的工人的挤出可以理解为劳动力市场对逆向选择问题的反应。当高技能工人申请技能密集程度较低的工作时，当雇佣合同不能系统地歧视教育水平时，就会出现逆向选择，即使资格过高的工人更有可能辞职。为了将工人分开，均衡扭曲了受教育程度低、失业率高的工人的劳动力市场结果。此外，这种扭曲创造了专上职业教育的市场价值，因为它起到了进入壁垒的作用，可以保护受教育程度较低的工人免受高素质大学毕业生的竞争。