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 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...

Taxing consumption in the digital economy poses unique challenges for fiscal authorities. Recent institutional reforms, such as states changing remittance rules for the sales and use tax following the Supreme Court decision in South Dakota v. Wayfair, were enacted in order to increase tax...

We study peer influence in an online social network on a platform where consumers purchase music albums. They can follow their peers and become informed about their consumption choices. In particular, we are interested in how this affects consumers' exploration of new music that exhibits...

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...

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 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...

We provide a practical guide to designing, conducting, and analyzing experiments using social media platforms. First, we discuss the benefits and challenges of using the targeting capabilities of advertisements on social media to recruit participants for a large class of experiments. Next, we...