Tracking online user behavior is essential for targeted advertising and is at the heart of the business model of major online platforms. We analyze tracker-specific web browsing data to show how the prediction quality of consumer profiles varies with data size and scope. We find decreasing...

We study a dynamic model with two competing durable goods; one dirty, the other clean. Due to network effects a consumer who adopts the dirty good today will increase the incentive future consumers have to adopt the dirty good. Thus, a consumer who chooses the dirty good, in a sense causes more...

We consider the effects of taxes for competing two-sided platforms. We first detail how a platform passes a tax increase on its prices. Adding price competition, we study next how the tax affects profits. Because of the strategic implications of the cross-side external effects, the tax increase...

We propose an analysis of platform competition based on the academic literature with a view towards competition policy. First, we discuss to which extent competition can emerge in digital markets and show which forms it can take. In particular, we underline the role of dynamics, but also of...

Platform interoperability is considered a powerful tool to promote competition in digital markets when network effects are at play. We study the effect of interoperability on competition between two ad-financed platforms, allowing for endogenous multi-homing of consumers. When the platforms are...