Public authorities in many jurisdictions are concerned about the proliferation of illegal content and products on online platforms. One often discussed solution is to make the platform liable for third parties’ misconduct. In this paper, we first identify platform incentives to stop online misconduct in the absence of liability. Then, we provide an economic appraisal of platform liability that highlights the intended and unintended effects of a more stringent liability rule on several key variables such as prices, terms and conditions, business models, and investments. Specifically, we discuss the impact of the liability regime applying to online platforms on competition between them and the incentives of third parties relying on them. Finally, we analyze the potential costs and benefits of measures that have received much attention in recent policy discussions.

许多司法管辖区的公共当局都担心在线平台上非法内容和产品的泛滥。一种经常讨论的解决方案是让平台对第三方的不当行为负责。在本文中，我们首先确定了在没有责任的情况下阻止在线不当行为的平台激励措施。然后，我们提供了平台责任的经济评估，突出了有意和无意的更严格的责任规则对价格、条款和条件、商业模式和投资等几个关键变量的影响。具体来说，我们讨论了适用于在线平台的责任制度对它们之间的竞争的影响以及依赖它们的第三方的激励。最后，我们分析了近期政策讨论中备受关注的措施的潜在成本和收益。