混合平台上提高竞争对手成本：费用与自我优待的互补性
Raising Rivals' Costs on Hybrid Platforms: The Complementarity of Fees and Self-Preferencing
AI总结：
该研究针对混合平台的费用与自我优待两种工具，建模发现二者为战略互补，单一工具监管有效，且二者可实现垄断效果却通过传统反垄断测试，为相关监管提供了理论依据。
AI中文摘要：
混合平台通过平台费用和自我优待对第三方卖家不利，监管机构担忧限制任一工具可能会加剧另一工具的影响。我们对同时选择两种工具的平台进行建模，发现结论相反：单一工具监管是有效的，因为这两种工具是战略互补的，监管任一工具都会抑制另一种工具。我们还发现，这两种工具能实现垄断带来的高价格和降低的消费者福利，且通过了所有传统反垄断测试。
英文摘要：
Hybrid platforms disadvantage third-party sellers through the platform fee and self-preferencing, and regulators have worried that constraining either instrument may intensify the other. We model a platform that chooses both instruments and find the opposite: single-instrument regulation is effective because the instruments are strategic complements, and regulating either instrument curbs the other. We also find that the two instruments achieve what monopolization achieves, higher prices and reduced consumer welfare, while passing every conventional antitrust test.
