Mudit DHAKAR will defend his thesis on Tuesday 09th September 2025 at 02:00 PM (Online)
Title: Essays in Industrial Organization
Supervisors: Professors Renato GOMES and Doh-Shin JEON
To attend the conference, please contact the secretariat of the TSE Doctoral school.
Memberships are:
- Renato GOMES : Senior Researcher, CNRS/TSE-R supervisor
- Doh-Shin JEON : Professor in Economics, Ecole TSE, co-supervisor
- Marc BOURREAU : Professor in Economics, Institut Polytechnique de Paris Rapporteur
- Senay SOKULLU : Associate professor in Economics, University of Bristol Rapporteure
Abstract :
This thesis consists of three chapters in the field of Industrial Organization. The first two chapters address topics in digital economics, while the third chapter focuses on sustainability in aviation. Each chapter is motivated by the contemporary policy debates relevant at the time of writing.
The first chapter investigates the effects of mandating interoperability between messaging services. We examine a situation in which a high-privacy paid niche app competes with a low-privacy free app with a large installed user base. Consumers differ in their privacy concerns and can multi-home across different apps. We find that niche app users may be worse off under partial privacy-preserving interoperability compared to no interoperability. Moreover, full interoperability may not necessarily promote market contestability, especially when privacy concerns significantly outweigh network benefits. We identify a misalignment between the low-privacy app’s incentives for interoperability and the welfare of niche app users, highlighting the importance of mandating a carefully calibrated level of interoperability. These results hold even when interoperability leads to privacy loss for users who opt into the policy.
The second chapter examines the impacts of a data sharing policy in innovative markets. We consider products with two-dimensional quality: one driven by data-enabled learning and the other by standalone innovation. By allowing firms to compete on these dimensions, we study the implications of differences in data collected across firms on the incentives to invest in standalone quality in a two-period model and show that the investment by a data-lagging firm increases as data dominance shrinks. We then explore the use of a deterministic full data sharing policy to reduce the data dominance. While such a policy always improves upon the innovation level, it can reduce consumer surplus in some cases, and we provide a sufficient condition for cases where consumer surplus improves.
The third chapter addresses the design of tax instruments to reduce emissions from the aviation sector. We compare taxes on airport charges with more conventional instruments such as fuel taxes, focusing on their effectiveness in discouraging air travel. We find that, while long-haul flight passengers have a higher tax burden with fuel taxes compared to short-haul passengers, taxes on airport charges affect all types of passengers equally and are more effective at discouraging short-haul traffic, which tends to be more polluting and more substitutable (with other transport modes) compared to long-haul. In addition, we find that a tax on airport charges can be effectively used to compensate airports for losses from reduced traffic.
