Regulating Platform Fees
研究了帮助消费者发现和交易供应商的平台，发现有效平台费用等于边际成本加上供应商在直销渠道与平台渠道加价之差，并探讨该公式作为监管上限的稳健性。
Abstract We consider platforms that help consumers discover and transact with suppliers. Such platforms have come to dominate many sectors of the economy, raising issues about the high fees they charge suppliers, especially since they tend to commoditize the suppliers they aggregate. We show that in a baseline setting, the efficient platform fee is determined by a simple formula: it equals the platform’s marginal cost plus the difference between suppliers’ markups on the direct channel and suppliers’ markups on the platform. We explore the extent to which this simple formula provides a robust cap for regulating the platform’s fee more generally.