Academic papers

Content and Advertising in Social Media Platforms (with L. Madio).
Journal of  Economics and Management Strategy, 2024.
Last SSRN version 

Abstract - 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 advertisers face. The platform is likely to under-moderate unsafe content relative to the socially desirable level when both advertisers and users have congruent preferences for unsafe content and to over- moderate unsafe content when advertisers have conflicting preferences for unsafe content. Finally, to mitigate negative externalities generated by unsafe content, we study the implications of a policy that mandates binding content moderation to online platforms and how the introduction of taxes on social media activity and social media platform competition can distort the platform’s moderation strategies.

The Welfare Effects of Mobile Internet Access : Evidence from Roam-Like-At-Home (with M. Godinho de Matos and C. Peukert).
The Economic Journal, 2023.
Last CESifo working paper version

Abstract - We evaluate the welfare effects of the Roam-Like-At-Home regulation, which drastically reduced the price of accessing the mobile internet for EU residents when traveling abroad in the European Economic Area. Estimates from individual-level usage data suggest that consumer surplus increased by 2.77 EUR/user/travel day. A decomposition shows the heterogeneous impact of the regulation on different user segments. We estimate that around half of the gains stem from a reduction in deadweight loss, i.e., new users accessing the mobile internet. We further show that the impact of the regulation varies with usage intensity abroad and at home, by the nature of the trip (leisure vs. business), and by content type. We discuss implications for content providers and other policy areas such as net neutrality.

Does Generative AI Erode Its Own Training Data?  Empirical Evidence of the Effects on Data Quantity and Characteristics from a Q\&A Platform (with D. Gutt).
R & R at Journal of  Management Information Systems.
Last SSRN version

Abstract - How do generative artificial intelligences (GAIs) affect their own training data such as that from Q\&A platforms? The Paradox of Reuse Theory posits that GAI usage would substitute traffic to Q\&A platforms where the training data originates. However, it remains an open question whether and how this affects subsequent training data generation on these platforms. We address this question by leveraging the launch of ChatGPT and using rich StackExchange panel data. We find a decrease in the number of questions on the platform, driven by platform abandonment of casual users, but the remaining questions are the more complex ones and exhibit novelty. Further investigation illustrates that the more the number of questions decreases, the more the remaining questions increase in complexity and novelty. These findings support the development of the Paradox of Reuse Theory by illuminating a special case in which training data erosion may be beneficial to the GAI.

Payment Instruments, Financial Privacy and Online Purchases (with Y. Balgobin, D. Bounie and P. Waelbroeck)
Review of Network Economics, 2017.
Last SSRN version

Abstract - The protection of financial personal data has become a major concern for Internet users in the digital economy. This paper investigates whether the consumers’ use of non-bank payment instruments that preserve financial privacy from banks and relatives may increase their online purchases. We analyze the purchasing decisions and the use of bank and non-bank payment instruments of a representative sample of French Internet consumers in 2015. Using two econometric methods, namely a two-step regression and a Bayesian Markov Chain Monte Carlo model to account for a potential endogeneity problem, we find evidence that the use of a non-bank payment instrument positively influences consumers’ online purchases. 

The Returns to Targeting: Evidence from a Field Experiment (with P. Ferreira, M. Godinho de Matos & C. Peukert).
Working paper.

Others

Advertising Viewability in Online Branding Campaigns (with D. Bounie and V. Morrisson)
Digiworld Economic Journal, No. 104 - 4th quarter 2016.
Last SSRN version 

Abstract - A significant number of online ads served by publishers are actually never seen by Internet users. This results in ineffective branding campaigns and a considerable waste of money for advertisers. In reaction, more and more advertisers use technologies to measure the viewability of advertising campaigns on publisher websites. This paper discusses how the adoption of such technologies could impact the economics of online advertising. 

Do You See What I See? Ad Viewability and the Economics of Online Advertising  (with D. Bounie and V. Morisson).
SSRN

Abstract - Between 40% and 50% of online ads served by publishers are actually never seen by Internet users, resulting in ineffective branding campaigns and a considerable waste of money for advertisers. In reaction, more and more advertisers use technologies to measure the viewability of advertising campaigns on publisher websites. This paper provides the first comprehensive economic analysis of the impact of the adoption of such technologies on the economics of online advertising. We construct a two-sided market model for advertising where publishers manage their website to attract Internet users and advertisers. We show that the adoption of ad viewability technology affects the number of viewable ads displayed by publishers, the price of ads and publisher profits, and user experience. We finally analyze the total welfare impact of ad viewability and examine how ad-blockers constrain publishers from both sides of the market.