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...

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 paper quantifies the impact of online vaccine skepticism on pediatric vaccine uptake and health outcomes. We propose a novel methodology that combines Natural Language Processing and an instrumental variable strategy that leverages the intransitivity of the social network's connections. By...

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...

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...

This paper studies the impact of Generative AI technologies on the demand for online freelancers using a large dataset from a leading global freelancing platform. We identify the types of jobs that are more affected by Generative AI and quantify the magnitude of the heterogeneous impact. Our...

In 2018, the European Council and the UK and Spanish governments each proposed to introduce a Digital Services Tax (DST), to be levied on the revenue of large digital platforms from advertising, online intermediation, and/or the transmission of data. We offer a rationalization of the DST as a...

Through social media, politicians can personalize their campaigns and target specific groups of voters with an unprecedented precision. We assess the effects of such political micro-targeting by exploiting daily advertising prices on Facebook during the 2016 US presidential campaign. We measure...

The adtech industry plays a key role in facilitating connections between digital publishers and advertisers. This paper studies the impact of vertical integration between an intermediary and a major publisher on the online advertising ecosystem and the provision of content. We find that vertical...

As social and business activities undergo significant digital transformation, the allure of digitized versus traditional in-person events remains a critical question. This study quantifies the heterogeneous effect of digitization on community participation across communities catering to...