{"scopus_import":"1","publication_status":"published","oa_version":"Preprint","type":"conference","volume":9470,"page":"230–243","publisher":"Springer Nature","publication_identifier":{"issn":["0302-9743"],"eisbn":["9783662489956"],"isbn":["9783662489949"]},"main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.1509.09147"}],"publication":"11th International Conference on Web and Internet Economics","citation":{"ista":"Cheung YK, Henzinger MH, Hoefer M, Starnberger M. 2015. Combinatorial auctions with conflict-based externalities. 11th International Conference on Web and Internet Economics. WINE: International Conference on Web and Internet Economics, LNCS, vol. 9470, 230–243.","mla":"Cheung, Yun Kuen, et al. “Combinatorial Auctions with Conflict-Based Externalities.” <i>11th International Conference on Web and Internet Economics</i>, vol. 9470, Springer Nature, 2015, pp. 230–243, doi:<a href=\"https://doi.org/10.1007/978-3-662-48995-6_17\">10.1007/978-3-662-48995-6_17</a>.","ama":"Cheung YK, Henzinger MH, Hoefer M, Starnberger M. Combinatorial auctions with conflict-based externalities. In: <i>11th International Conference on Web and Internet Economics</i>. Vol 9470. Springer Nature; 2015:230–243. doi:<a href=\"https://doi.org/10.1007/978-3-662-48995-6_17\">10.1007/978-3-662-48995-6_17</a>","ieee":"Y. K. Cheung, M. H. Henzinger, M. Hoefer, and M. Starnberger, “Combinatorial auctions with conflict-based externalities,” in <i>11th International Conference on Web and Internet Economics</i>, Amsterdam, Netherlands, 2015, vol. 9470, pp. 230–243.","apa":"Cheung, Y. K., Henzinger, M. H., Hoefer, M., &#38; Starnberger, M. (2015). Combinatorial auctions with conflict-based externalities. In <i>11th International Conference on Web and Internet Economics</i> (Vol. 9470, pp. 230–243). Amsterdam, Netherlands: Springer Nature. <a href=\"https://doi.org/10.1007/978-3-662-48995-6_17\">https://doi.org/10.1007/978-3-662-48995-6_17</a>","chicago":"Cheung, Yun Kuen, Monika H Henzinger, Martin Hoefer, and Martin Starnberger. “Combinatorial Auctions with Conflict-Based Externalities.” In <i>11th International Conference on Web and Internet Economics</i>, 9470:230–243. Springer Nature, 2015. <a href=\"https://doi.org/10.1007/978-3-662-48995-6_17\">https://doi.org/10.1007/978-3-662-48995-6_17</a>.","short":"Y.K. Cheung, M.H. Henzinger, M. Hoefer, M. Starnberger, in:, 11th International Conference on Web and Internet Economics, Springer Nature, 2015, pp. 230–243."},"date_created":"2022-08-08T13:54:32Z","year":"2015","doi":"10.1007/978-3-662-48995-6_17","abstract":[{"lang":"eng","text":"Combinatorial auctions (CA) are a well-studied area in algorithmic mechanism design. However, contrary to the standard model, empirical studies suggest that a bidder’s valuation often does not depend solely on the goods assigned to him. For instance, in adwords auctions an advertiser might not want his ads to be displayed next to his competitors’ ads. In this paper, we propose and analyze several natural graph-theoretic models that incorporate such negative externalities, in which bidders form a directed conflict graph with maximum out-degree Δ. We design algorithms and truthful mechanisms for social welfare maximization that attain approximation ratios depending on Δ.\r\n\r\nFor CA, our results are twofold: (1) A lottery that eliminates conflicts by discarding bidders/items independent of the bids. It allows to apply any truthful 𝛼-approximation mechanism for conflict-free valuations and yields an 𝒪(𝛼Δ)-approximation mechanism. (2) For fractionally sub-additive valuations, we design a rounding algorithm via a novel combination of a semi-definite program and a linear program, resulting in a cone program; the approximation ratio is 𝒪((ΔloglogΔ)/logΔ). The ratios are almost optimal given existing hardness results.\r\n\r\nFor adwords auctions, we present several algorithms for the most relevant scenario when the number of items is small. In particular, we design a truthful mechanism with approximation ratio 𝑜(Δ) when the number of items is only logarithmic in the number of bidders."}],"day":"09","article_processing_charge":"No","oa":1,"date_published":"2015-12-09T00:00:00Z","_id":"11774","author":[{"full_name":"Cheung, Yun Kuen","last_name":"Cheung","first_name":"Yun Kuen"},{"last_name":"Henzinger","full_name":"Henzinger, Monika H","id":"540c9bbd-f2de-11ec-812d-d04a5be85630","first_name":"Monika H","orcid":"0000-0002-5008-6530"},{"first_name":"Martin","last_name":"Hoefer","full_name":"Hoefer, Martin"},{"last_name":"Starnberger","full_name":"Starnberger, Martin","first_name":"Martin"}],"title":"Combinatorial auctions with conflict-based externalities","status":"public","extern":"1","month":"12","intvolume":"      9470","external_id":{"arxiv":["1509.09147"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","alternative_title":["LNCS"],"conference":{"end_date":"2015-12-12","start_date":"2015-12-09","location":"Amsterdam, Netherlands","name":"WINE: International Conference on Web and Internet Economics"},"quality_controlled":"1","date_updated":"2023-02-10T09:08:30Z","language":[{"iso":"eng"}]}