This paper studies the effect of advertising on content differentiation on YouTube, the second-most visited website in the world. I demonstrate that an exogenous increase in the feasible advertising quantity leads to a considerable decrease in the YouTubers' probability to duplicate mainstream...

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...

This article reports on an investigation of the role of lock-in exploitation and the impact of reputation portability on workers’ switching behaviors in online labor markets. Online platforms using reputation mechanisms typically prevent users from transferring their ratings to other...

We study the effects of taxation on the international online advertising market, using data on Facebook ad prices, Facebook users product preferences and international trade. Our data encompass a de facto increase in the platform's corporate tax rate in several countries. We show that, due to...

This study investigates the effects of variation in "congeniality" of news on Facebook user engagement (likes, shares, and comments). We compile an original data set of Facebook posts by 84 German news outlets on politicians that were investigated for criminal offenses from January 2012 to June...

We use a novel dataset of online advertiser performance and product sales to quantify the medium-term economic effects of Apple's App Tracking Transparency Policy (ATT). We find that ATT significantly degraded the ability by Facebook advertisers to target advertisements based on its off-platform...

Does online fundraising increase charitable giving? Using the Facebook advertising tool, we implemented a natural field experiment across Germany, randomly assigning almost 8,000 postal codes to Save the Children fundraising videos or to a pure control. We studied changes in the donation revenue...

I study demand for social media services by conducting an experiment where I monitor how participants spend time on digital services and shut off access to Instagram or YouTube on their mobile phones. I characterize how participants substitute their time during and after the restrictions, which...

We study the incentive of an ad-funded social media platform to curb the presence of unsafe content that entails reputational risk to advertisers. We identify conditions for the platform not to moderate unsafe content and demonstrate how the optimal moderation policy depends on the risk the...

We examine the long-run effect of homophily in online social networks on interpersonal interactions in local communities. We measure online homophily across counties in the US using Facebook data. For identification, we exploit a conflict between Facebook and Google over data sharing of user...