Monday, November 16, 2009
11:00 AM
Computer Studies Bldg. Room 209
Lane A. Hemaspaandra
University of Rochester
The Shield that Never Was: Societies with Single-Peaked Preferences Are More Open to Manipulation and Control
Much work has been devoted, during the past twenty years, to using complexity to protect elections from manipulation and control. Many results have been obtained showing NP-hardness shields, and recently there has been much focus on whether such worst-case hardness protections can be bypassed by frequently correct heuristics or by approximations. Our work takes a very different approach: We argue that when electorates follow the canonical political science model of societal preferences the complexity shield never existed in the first place. In particular, we show that for electorates having single-peaked preferences, many existing NP-hardness results on manipulation and control evaporate. This talk is on joint work with Piotr Faliszewski, Edith Hemaspaandra, and Joerg Rothe.

Refreshments will be provided at 10:30AM