There are increasingly many examples of people voting over the Internet. In such elections, it is often possible for a single person to vote multiple times. What can we do to address this? I will discuss a variety of possible approaches, including: trying to remove incentives for voting more than once altogether; using social network structure to identify suspect votes; and statistical evaluation of approaches that hinder, but do not completely prevent, casting multiple votes (for example, using a CAPTCHA or allowing only one vote per IP address).
Bio: Vincent Conitzer is the Sally Dalton Robinson Professor of Computer Science and Professor of Economics at Duke University. He received Ph.D. (2006) and M.S. (2003) degrees in Computer Science from Carnegie Mellon University, and an A.B. (2001) degree in Applied Mathematics from Harvard University. His research focuses on computational aspects of microeconomics, in particular game theory, mechanism design, voting/social choice, and auctions. This work uses techniques from, and includes applications to, artificial intelligence and multiagent systems. Conitzer has received the IJCAI Computers and Thought Award, recognition as one of "AI's Ten to Watch" by IEEE Intelligent Systems, an NSF CAREER award, a Sloan fellowship, the inaugural Victor Lesser dissertation award, an honorable mention for the ACM dissertation award, and several awards for papers and service at the AAAI and AAMAS conferences. Conitzer and Preston McAfee are the founding Editors-in-Chief of the ACM Transactions on Economics and Computation (TEAC).