Ranking algorithms are the information gatekeepers of the Internet era. We develop a stylized framework to study the effects of ranking algorithms on opinion dynamics. We consider rankings that depend on popularity and on personalization. We find that popularity driven rankings can enhance...

Digital media goods and digital media platforms exhibit cost structures and network effects that imply that price and quantity effects of consumption taxes are qualitatively different compared to what we typically find for physical goods. For instance, in most European countries and US states,...

This paper uses the 2015 Volkswagen emissions scandal as a natural experiment to provide causal evidence that group reputation externalities matter for firms. Our estimates show statistically and economically significant declines in the U.S. sales and stock returns of, as well as public...

We quantify the prevalence of undisclosed influencer posts on Twitter across a large set of brands based on a unique data set of over 100 million posts. We develop a novel method to detect undisclosed influencer posts and find that 96% of influencer posts are not disclosed as such. Despite...

Search engines are important access channels to news content of traditional newspapers with Google alone responsible for 35% of online visits to news outlets in the European Union. Yet, the effects of Google Search on market competition and information diversity have received scant attention....

This study documents the existence and prevalence of the “review updating” phenomenon, where consumers change the ratings and content of their existing reviews, and examines its implications for platforms and businesses. Using both primary and secondary data, a dataset comprising 3 million...

We investigate the relation between Net Neutrality regulation and Internet fragmentation. We model a two-sided market, where Content Providers (CPs) and consumers interact through Internet Service Providers (ISPs), and CPs sell consumers' attention to advertisers. Under Net Neutrality, a...

A large literature studies subjective beliefs about economic facts using unincentivized survey questions. We devise randomized experiments in a representative online survey to investigate whether incentivizing belief accuracy affects stated beliefs about average earnings by professional degree...

In this paper, we study the effects of a self-regulatory effort, orchestrated by the European Commission, that aims to reduce advertising revenues for publishers of copyright infringing content. Historical data lets us follow how the third-party advertising and tracking services associated with...