When a consumer pays by card, the merchant’s bank pays to the consumer’s bank an interchange fee. In this article, we construct a general model of a card platform that unifies the literature on interchange fees. We enrich the existing frameworks by analyzing the choice of the interchange fee when consumer demand is elastic to retail prices. We show that the difference between the privately set structure of payment card fees and the socially optimal one depends both onbanks’ andmerchants’ pass-throughof their costs to consumers.Weargue that the maturity of the payment card market impacts the redistributive effects of interchange fees (i.e. between consumers and merchants, card and cash users) and therefore, their optimal regulation.

中文翻译：

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谁支付卡付款？交换费作用的一般模型

当消费者用卡付款时，商人的银行向消费者的银行支付交换费。在本文中，我们构建了一个通用的卡平台模型，该模型统一了有关交换费的文献。当消费者需求对零售价格具有弹性时，我们通过分析交换费的选择来丰富现有框架。我们发现，私人设置的支付卡费用结构与社会最优支付结构之间的差异取决于银行和商人将其成本转嫁给消费者的情况。警告，支付卡市场的成熟度会影响交换费的再分配效应（ （例如，在消费者和商人之间，在卡和现金用户之间）以及因此，它们的最佳监管。