In a market where consumers choose between payment options and firms compete with products and prices, we show that payment data drives the formation of a market monopoly. A data-sharing policy can successfully restore and maintain a competitive market, but often at the expense of both...

Many companies are not satisfied with collecting only the personal information that customers provide during a transaction or sign-up, or even the additional personal information they collect about the customer’s activities on the company’s own website or app. Instead, there is a common...