Denial of interoperability and future first-party entry

Motivated by a recent antitrust case involving Google, we develop a rationale for foreclosure when the owner of an essential input is not yet integrated downstream. Our theory rests on data-enabled network effects across periods. If a platform considers offering a first-party app in the future, by not allowing a third-party app to be hosted on its platform, it ensures that the third-party app would be a weaker competitor to its own app in the future. This makes denial of access attractive as a full or partial foreclosure strategy, which is costly in the short term but may be beneficial in the long term. We also study the effects of policies such as compulsory access or data-sharing, showing under which conditions they might be beneficial to consumers or backfire.