中文摘要
立法规范着我们工作中的关键福利——带薪病假与休假、工作时间、安全的工作条件以及工伤补偿——而社会运动对其获得至关重要。为什么是法律、而非市场来保障这些福利？本文研究一种解释：生产率上的逆向选择。当更看重某项福利的工人平均而言生产率更低时，提供该福利的雇主就会吸引到生产率更低的劳动力。由此产生的补偿性工资差异超过了直接成本，导致供给不足——即便该福利是无成本的。我运用一种新的随机相依性概念——期望相关性——来形式化这一机制，它刻画了逆向选择的严重程度。在存在异质性工作的竞争性筛选均衡中，供给不足会随这一相关性的强度而加剧，在极端情形下，市场会完全瓦解。当相关性很强时，普适性强制是最优的；当相关性中等时，利用可观测异质性的政策——例如针对为人父母者的弹性权利——优于强制政策和自由放任。本文将此基于生产率的选择与既有研究中基于成本的选择加以对比，并讨论各自所蕴含的独特实证检验。
Abstract
Legislation regulates the key amenities of our jobs—paid sick leave and holidays, working hours, safe working conditions, and workers’ compensation—and social movements have been essential to their adoption. Why do laws, rather than markets, secure these amenities? This paper studies one answer: adverse selection on productivity. When workers who value an amenity more are, on average, less productive, employers offering it attract a lower-productivity workforce. The resulting compensating wage differential exceeds the direct cost, leading to underprovision—even when the amenity is costless. I formalize this mechanism using a new notion of stochastic dependence, the correlation in expectation , which captures the severity of adverse selection. In a competitive screening equilibrium with heterogeneous jobs, underprovision intensifies with the strength of this correlation and, in extreme cases, the market unravels entirely. A universal mandate is optimal when the correlation is strong; when it is moderate, policies leveraging observable heterogeneity—such as flexibility rights for parents—outperform both the mandate and laissez-faire. The paper contrasts this productivity-based selection with the traditional cost-based selection studied in prior work and discusses the distinct empirical tests each implies.