A lack of platform-level competition among digital marketplaces can result in socially inefficient platform design and meaningful welfare losses, even independent of actively anticompetitive behavior. To illustrate the first-order effects platform design can have on competitive outcomes, I...

This study compares the impact of antitrust regulations on firm market value for Chinese versus U.S. internet platforms. Applying an event study approach to daily stock market data during 2010–2022, we investigate the cumulative abnormal returns of Hong Kong- and U.S.-listed internet...