Online market intermediation
Giannakopoulos Y, Koutsoupias E, Lazos P (2017)
Publication Type: Conference contribution, Original article
Publication year: 2017
Journal
Publisher: Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing
Book Volume: 80
Pages Range: 47:1--47:14
Conference Proceedings Title: Leibniz International Proceedings in Informatics, LIPIcs
Event location: Warsaw
ISBN: 9783959770415
DOI: 10.4230/LIPIcs.ICALP.2017.47
Open Access Link: https://arxiv.org/abs/1703.09279
Abstract
We study a dynamic market setting where an intermediary interacts with an unknown large sequence of agents that can be either sellers or buyers: their identities, as well as the sequence length n, are decided in an adversarial, online way. Each agent is interested in trading a single item, and all items in the market are identical. The intermediary has some prior, incomplete knowledge of the agents' values for the items: all seller values are independently drawn from the same distribution FS, and all buyer values from FB. The two distributions may differ, and we make common regularity assumptions, namely that FB is MHR and FS is log-concave. We focus on online, posted-price mechanisms, and analyse two objectives: that of maximizing the intermediary's profit and that of maximizing the social welfare, under a competitive analysis benchmark. First, on the negative side, for general agent sequences we prove tight competitive ratios of θ(σn) and θ(ln n), respectively for the two objectives. On the other hand, under the extra assumption that the intermediary knows some bound on the ratio between the number of sellers and buyers, we design asymptotically optimal online mechanisms with competitive ratios of 1+o(1) and 4, respectively. Additionally, we study the model where the number of items that can be stored in stock throughout the execution is bounded, in which case the competitive ratio for the profit is improved to O(ln n).
Authors with CRIS profile
Involved external institutions
United Kingdom (GB)
Germany (DE)How to cite
APA:
Giannakopoulos, Y., Koutsoupias, E., & Lazos, P. (2017). Online market intermediation. In Anca Muscholl, Piotr Indyk, Fabian Kuhn, Ioannis Chatzigiannakis (Eds.), Leibniz International Proceedings in Informatics, LIPIcs (pp. 47:1--47:14). Warsaw, PL: Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing.
MLA:
Giannakopoulos, Yiannis, Elias Koutsoupias, and Philip Lazos. "Online market intermediation." Proceedings of the 44th International Colloquium on Automata, Languages, and Programming, ICALP 2017, Warsaw Ed. Anca Muscholl, Piotr Indyk, Fabian Kuhn, Ioannis Chatzigiannakis, Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing, 2017. 47:1--47:14.
BibTeX: Download