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SUMMARY:Cooperation\, Power and Conspiracies - Yoram Bachrach\, Microsoft 
 Research
DTSTART:20110124T100000Z
DTEND:20110124T110000Z
UID:TALK29410@talks.cam.ac.uk
CONTACT:Microsoft Research Cambridge Talks Admins
DESCRIPTION:Cooperative game theory is all about how selfish agents might 
 agree to collaborate and then share their spoils. \nIt allows answering qu
 estions such as:\n- Can a political party increase its influence by splitt
 ing into two parties?\n- How would owners of compute clusters agree to sha
 re the gains from running a task in the cloud?\n- What conspiracies could 
 allow advertisers on our Bing platform to lower their costs at our expense
 ?\n\nCooperation can be problematic when agents collaborate to attack a po
 litical or economic system. For example\, agents participating in an aucti
 on can coordinate their bids in order to pay less for obtaining their item
 s and political parties may strategically merge or split to increase their
  influence. In weighted voting games\, a known model for decision-making b
 odies\, false-name attacks where agents merge and split can dramatically i
 nfluence the distribution of power. Similarly\, auctions based on the VCG 
 mechanism are excellent in achieving truthful bids and an optimal allocati
 on when agents do not cooperate\, but are very susceptible to collusion. I
  will demonstrate such attacks in political systems and multi-unit auction
 s\, showing how the colluders can find their optimal joint attack strategi
 es and reasonable agreements for sharing the gains. The analysis for both 
 domains is based on the core and the Shapley value\, prominent solution co
 ncepts from cooperative game theory.\n\nFinally\, I will consider the impl
 ications of such attacks for cloud computing environments and sponsored se
 arch auctions on Bing.\n
LOCATION:Small lecture theatre\, Microsoft Research Ltd\, 7 J J Thomson Av
 enue (Off Madingley Road)\, Cambridge
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