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True Costs of Cheap Labor Are Hard To Measure: Edge Deletion and VCG Payments in Graphs

True Costs of Cheap Labor Are Hard To Measure: Edge Deletion and VCG Payments in Graphs
True Costs of Cheap Labor Are Hard To Measure: Edge Deletion and VCG Payments in Graphs
We address the problem of lowering the buyer's expected payments in shortest path auctions, where the buyer's goal is to purchase a path in a graph in which edges are owned by selfish agents. We show that by deleting some of the edges of the graph, one can reduce the total payment of the VCG mechanism by a factor of $\Theta(n)$. However, we prove that it is NP-hard to find the best subset of edges to delete, even if the edge costs are small integers, or the graph has very simple structure; in the former case, this problem is hard to approximate, too. On the positive side, we describe a pseudopolynomial time algorithm for series-parallel graphs and fixed edge costs. Also, we discuss the applicability of this algorithm for the case of general (probabilistic) costs and derive a general lower bound on the performance of algorithms that are based on expected edge costs.
108-116
Elkind, Edith
7a013473-5cd0-4e41-b907-66b30a04a400
Riedl, John
21aae74d-fcdf-432d-9d43-d86fc11b7c43
Kearns, Michael J.
34739b48-dc6a-4a3a-b3c8-7ff2b18dab21
Reiter, Michael K.
c8ed2f4e-85c3-4cf0-aa7b-027f76123e8a
Elkind, Edith
7a013473-5cd0-4e41-b907-66b30a04a400
Riedl, John
21aae74d-fcdf-432d-9d43-d86fc11b7c43
Kearns, Michael J.
34739b48-dc6a-4a3a-b3c8-7ff2b18dab21
Reiter, Michael K.
c8ed2f4e-85c3-4cf0-aa7b-027f76123e8a

Elkind, Edith (2005) True Costs of Cheap Labor Are Hard To Measure: Edge Deletion and VCG Payments in Graphs. Riedl, John, Kearns, Michael J. and Reiter, Michael K. (eds.) 6th ACM Conference on Electronic Commerce (EC-2005), Vancouver, Canada. 05 - 08 Jun 2005. pp. 108-116 .

Record type: Conference or Workshop Item (Paper)

Abstract

We address the problem of lowering the buyer's expected payments in shortest path auctions, where the buyer's goal is to purchase a path in a graph in which edges are owned by selfish agents. We show that by deleting some of the edges of the graph, one can reduce the total payment of the VCG mechanism by a factor of $\Theta(n)$. However, we prove that it is NP-hard to find the best subset of edges to delete, even if the edge costs are small integers, or the graph has very simple structure; in the former case, this problem is hard to approximate, too. On the positive side, we describe a pseudopolynomial time algorithm for series-parallel graphs and fixed edge costs. Also, we discuss the applicability of this algorithm for the case of general (probabilistic) costs and derive a general lower bound on the performance of algorithms that are based on expected edge costs.

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More information

Published date: 2005
Additional Information: Event Dates: June 5-8, 2005
Venue - Dates: 6th ACM Conference on Electronic Commerce (EC-2005), Vancouver, Canada, 2005-06-05 - 2005-06-08
Organisations: Electronics & Computer Science

Identifiers

Local EPrints ID: 263440
URI: http://eprints.soton.ac.uk/id/eprint/263440
PURE UUID: 4ffbee57-ade3-43bc-b094-8d8b581233d5

Catalogue record

Date deposited: 15 Feb 2007
Last modified: 14 Mar 2024 07:31

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Contributors

Author: Edith Elkind
Editor: John Riedl
Editor: Michael J. Kearns
Editor: Michael K. Reiter

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