3,033 research outputs found
Multi-unit Auction over a Social Network
Diffusion auction is an emerging business model where a seller aims to
incentivise buyers in a social network to diffuse the auction information
thereby attracting potential buyers. We focus on designing mechanisms for
multi-unit diffusion auctions. Despite numerous attempts at this problem,
existing mechanisms either fail to be incentive compatible (IC) or achieve only
an unsatisfactory level of social welfare (SW). Here, we propose a novel graph
exploration technique to realise multi-item diffusion auction. This technique
ensures that potential competition among buyers stay ``localised'' so as to
facilitate truthful bidding. Using this technique, we design multi-unit
diffusion auction mechanisms MUDAN and MUDAN-. Both mechanisms satisfy,
among other properties, IC and -weak efficiency. We also show that they
achieve optimal social welfare for the class of rewardless diffusion auctions.
While MUDAN addresses the bottleneck case when each buyer demands only a single
item, MUDAN- handles the more general, multi-demand setting. We further
demonstrate that these mechanisms achieve near-optimal social welfare through
experiments
Core-stable Rings in Second Price Auctions with Common Values
In a common value auction in which the information partitions of the bidders are connected, all rings are core-stable. More precisely, the ex ante expected utilities of rings, at the (noncooperative) sophisticated equilibrium proposed by Einy, Haimanko, Orzach and Sela (Journal of Mathematical Economics, 2002), describe a cooperative game, in characteristic function form, in spite of the underlying strategic externalities. A ring is core-stable if the core of this characteristic function is not empty. Furthermore, every ring can implement its sophisticated equilibrium strategy by means of an incentive compatible mechanism.Auctions, Bayesian Game, Collusion, Core, Partition Form Game, Characteristic Function
Mechanism Design in Social Networks
This paper studies an auction design problem for a seller to sell a commodity
in a social network, where each individual (the seller or a buyer) can only
communicate with her neighbors. The challenge to the seller is to design a
mechanism to incentivize the buyers, who are aware of the auction, to further
propagate the information to their neighbors so that more buyers will
participate in the auction and hence, the seller will be able to make a higher
revenue. We propose a novel auction mechanism, called information diffusion
mechanism (IDM), which incentivizes the buyers to not only truthfully report
their valuations on the commodity to the seller, but also further propagate the
auction information to all their neighbors. In comparison, the direct extension
of the well-known Vickrey-Clarke-Groves (VCG) mechanism in social networks can
also incentivize the information diffusion, but it will decrease the seller's
revenue or even lead to a deficit sometimes. The formalization of the problem
has not yet been addressed in the literature of mechanism design and our
solution is very significant in the presence of large-scale online social
networks.Comment: In The Thirty-First AAAI Conference on Artificial Intelligence, San
Francisco, US, 04-09 Feb 201
Merger Mechanisms
A firm can merge with one of n potential partners. The owner of each firm has private information about both his firmâs stand-alone value and a component of the synergies that would be realized by the merger involving his firm. We characterize incentive-efficient mechanisms in two cases. First, we assume that the value of any newly formed partnership is verifiable, hence transfers can be made contingent on the new information accruing after the merger. Second, we study the case of uncontingent rules. In the first case, we show that it is not optimal, in general, to redistribute shares of non-merging firms, and identify necessary and sufficient conditions for the implementability of efficient merger rules. In the second case, we show that the first-best can be obtained i) always, if the synergy values are privately known but the firmsâ stand-alone values are observable; ii) only with sufficiently large synergies, if the firmsâ stand-alone are privately known; and iii) never, if the set of feasible mechanisms is restricted to âauctions in sharesâ.Mechanism design, Merger
Characterizations of Network Auctions and Generalizations of VCG
With the growth of networks, promoting products through social networks has
become an important problem. For auctions in social networks, items are needed
to be sold to agents in a network, where each agent can bid and also diffuse
the sale information to her neighbors. Thus, the agents' social relations are
intervened with their bids in the auctions. In network auctions, the classical
VCG mechanism fails to retain key properties. In order to better understand
network auctions, in this paper, we characterize network auctions for the
single-unit setting with respect to weak budget balance, individual
rationality, incentive compatibility, efficiency, and other properties. For
example, we present sufficient conditions for mechanisms to be efficient and
(weakly) incentive compatible. With the help of these properties and new
concepts such as rewards, participation rewards, and so on, we show how to
design efficient mechanisms to satisfy incentive compatibility as much as
possible, and incentive compatibility mechanisms to maximize the revenue. Our
results provide insights into understanding auctions in social networks.Comment: To appear in ECAI 202
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