The online grocery market has seen significant entry over the last five years by firms with different business models. Most firms offer subscriptions, and, in the data, consumers rarely switch between them. I find that switching costs significantly affect consumer platform choice, suggesting...

This paper develops an index of allocative efficiency that depends upon the distribution of mark-ups across goods. It determines how changes in trade frictions affect allocative efficiency in an oligopoly model of international trade, decomposing the effect into the cost-change channel and the...