中文摘要
劳动力市场并非完全竞争：买方垄断势力使雇主能够向工人支付低于劳动边际收益产品的工资。本文回顾了解释买方垄断势力的三种理论框架。寡头买方模型将其归因于数量有限的企业之间的战略互动。工作差异化模型强调工作之间的不完全替代以及工人偏好的异质性。搜寻与匹配模型则指出，搜寻摩擦阻碍了工人即时获取所有可得工作。随后，本文以理论为依据，讨论关于反垄断政策、降低工作转换壁垒的政策以及应对买方垄断势力对工人影响的政策的实证证据。阻止企业合并和规制竞业禁止协议，可以通过维持雇主之间的竞争来提高工资。最低工资能够在不减少就业的情况下提高工资，从而缓解买方垄断势力的影响。从理论模型和实证证据中获得的洞见，为制定能够增强劳动力市场竞争的政策提供了路线图。
Abstract
Labor markets are not perfectly competitive: Monopsony power enables employers to pay workers less than the marginal revenue product of labor. We review three theoretical frameworks explaining monopsony power. Oligopsony models attribute it to strategic interactions among a limited number of firms. Job differentiation models cite imperfect job substitution and heterogeneous worker preferences. Search-and-matching models point to search frictions hindering instantaneous access to all available jobs. We then develop a theory-informed discussion of the empirical evidence on antitrust policies, policies that reduce barriers to job switching, and policies countering monopsony's effects on workers. Preventing mergers and regulating noncompetition agreements can increase wages by preserving competition among employers. Minimum wages can mitigate the effect of monopsony power by increasing wages without reducing employment. The insights garnered from both theoretical models and empirical evidence offer a road map for crafting policies that can enhance competition in the labor market.