Wednesday, 8 September, 2021 | 13:00 | Defense - PhD

Jan Šedek: "Essays on Allocations in Two-Sided Markets"

Defense Committee:
Krešimir Žigić (chair)
Ole Jann
Ondřej Kalenda (Faculty of Mathematics and Physics, Charles University)

Dissertation Committee:
Antonio Miralles (Barcelona Graduate School of Economics)
Marco Serena (Max Planck Institute for Tax Law and Public Finance)

Dissertation Committee:
Jan Zápal (chair)
Jakub Steiner
Filip Matějka


Chapter 1 studies strategy-proofness in a congested market with asymmetric information and interdependences in players preferences. The market consists of players and depletable locations. Knowing about the asymmetries of information and interdependences in preferences, the players choose one of two locations. In case of congestion, the rejected players are costlessly allocated to the other location. We show that, under correlated preferences, asymmetric information causes strategy-proofness to fail. We further provide a characterization of strategy-proofness of the allocation mechanism. Finally, we provide several sufficient conditions for strategy-proofness including independence of preferences.

Chapter 2 studies information acquisition incentives and welfare in a congested market with independent preferences. The players first learn about their preferences over two locations, after which they choose a location. In case of congestion, the rejected players are costlessly allocated to the other location. First, we show that for independent preferences, the allocation game with information acquisition tends to exhibit complementarities in information acquisition. This results in equilibrium multiplicity. Second, we show that due to prevailing positive externalities the equilibrium, in which more agents learn, welfare-dominates the non-learning equilibrium. Finally, we show that abolishing uncertainty about allocation chances leads to a welfare improvement for the players. The results can be applied, for instance, to matching markets. In particular, the second welfare result can be applied to a school choice setting, in which randomization is often used to break ties. We argue that the welfare of students would be improved if tie-breaking occurred before information acquisition - a change which is technically possible to implement.

Chapter 3 studies a monopolistic platform's decision on how to allocate sellers to consumers in a two-sided market for depletable goods. We find that the platform recommends low quality sellers and thus facilitates sales of lower quality products in order to increase the size of the market. This is achieved by a mechanism in which the platform commits to a rule through which it diverts some demand from high quality products to low quality products in times of low demand in order to satisfy the participation constraint of low quality sellers and ensure they earn non-negative profits, and thereby enable them to stay on the market. The rule consequently increases the number of sellers on the market in times of high demand and the platform can extract additional profits through transaction fees.