We provide a model of online advertising display markets where consumer attention may be divided among multiple publishers and, consequently, their advertising attention may be allocated to different platforms. We demonstrate that this gives rise to a mixture of single- and multi-homing...

In media markets, consumers spread their attention to several outlets, increasingly so as consumption migrates online. The traditional framework for studying competition among media outlets rules out this behavior by assumption. We propose a new model that allows consumers to choose multiple...

This paper develops a fairly general model of platform competition in media markets allowing viewers to use multiple platforms. This leads to a new form of competition between platforms, in which they do not steal viewers from each other, but affect the viewer composition and thereby the...

Pricing decisions are increasingly in the “hands” of artificial algorithms. Scholars and competition authorities have voiced concerns that those algorithms are capable of sustaining collusive outcomes more effectively than human decision makers. If this is so, then our traditional policy...

This paper presents a broad retrospective evaluation of mergers and merger decisions in the digital sector. We first discuss the most crucial features of digital markets such as network effects, multi-sidedness, big data, and rapid innovation that create important challenges for competition...

We present a methodology for analyzing the impact of algorithmic recommendations on product market competition, addressing concerns that have been raised in both academic and policy circles regarding their potential anti-competitive effects. Our analysis demonstrates that recommender systems...

Payment card networks, such as Visa, require merchants' banks to pay substantial "interchange" fees to cardholders' banks, on a per transaction basis. This paper shows that a network's profit-maximizing fee induces an inefficient price structure, over-subsidizing card usage and over-taxing...