Jun YAN 's PhD Thesis, July 5th

July 05, 2022 Research

 Jun YAN  will defend her thesis on Tuesday 5 July at 09:30 AM (Auditorium 5)
« Three Essays on Digital Platforms and Competition Policy »
Supervisor: Professor Doh-Shin Jeon

To attend the conference, please contact the secretariat Elvire Jalran

Memberships are:

  • Doh-Shin JEON, Toulouse School of Economics, Ut1 Capitole, Directeur de thèse
  • Alexandre DE CORNIÈRE, Toulouse School of Economics, Ut1 Capitole, Co-directeur de thèse
  • Anna D'ANNUNZIO, Toulouse Business School, Rapporteure
  • Germain GAUDIN, University of Freiburg, Rapporteur
  • Claire CHAMBOLLE, INRAE, Examinatrice
  • Bruno JULLIEN, CNRS, Examinateur

Abstract :

This thesis consists of three independent chapters and examines different antitrust issues related to gatekeeper platforms. Chapter I explores the vertical foreclosure problem in two-sided markets. In the context of Google's Accelerated Mobile Pages (AMP), Chapter 2 examines the issue of gatekeeper platforms' access to business users' data. Chapter 3 focuses on digital copyright and studies Google's behavior of using publishers' content to display short answers on search result pages.
The first chapter examines how the vertical integration of a monopolistic platform, which is characterized by bilateral cross-group network externalities, impacts its incentive to engage in downstream foreclosure. I focus on an environment where the platform and downstream sellers face uncertainty over the gains from trade at the contracting stage. As the random shock is non-contractible, contracting creates friction that distorts the platform's pricing structure. By contrast, vertical integration mitigates this problem by allowing the platform to incorporate the random shock in consumer pricing. Due to the interaction between transaction friction and cross-group network externalities, I find that vertical integration could reduce the platform's incentive of foreclosure.
The second chapter is joint work with Doh-Shin Jeon. We study how newspapers' adoption of AMP, a publishing format that enables instant loading of web pages in mobile browsers, changes data allocation and thereby newspapers' incentives to invest in quality journalism. The adoption of AMP allows Google to obtain consumer data from AMP articles and to combine it with other sources of consumer data to improve the targeting of the advertisements served by Google on other websites. Even if such data combination increases static efficiency, it can reduce dynamic efficiency when it lowers the ad revenue per newspaper traffic, thereby reducing the quality of journalism. Newspapers face a collective action problem as a newspaper's adoption of AMP generates negative externalities to other newspapers through search ranking and data leakage. Google can leverage its market power in search and ad intermediation to induce newspapers to adopt AMP. We provide policy remedies.
The third chapter builds a theoretical model of divisible information goods to examine how a monopolistic search engine's use of snippets impacts content consumption and creation. By displaying snippets in the answer box on search result pages, the search engine unbundles the essential information and the supplemental information of articles. It, therefore, creates two opposite effects on publishers' incentive to invest in quality--the market size effect and the elasticity effect. Its impact on social welfare is ambiguous. On the one hand, the answer box improves search efficiency by providing broader access to essential information and allowing inframarginal consumers to substitute essential information for the full article. On the other hand, it could cut down website traffic, lowering publishers' advertising revenue and incentive to invest in quality. I examine the impacts of different policies that enforce the search engine to pay for the use of snippets.