Abstract
Cass Sunstein details intrinsic flaws in group discussion, even in ideal deliberation, and draws attention to prediction markets and information-aggregation devices on the internet as supplements to discussion. I respond that the supposed flaws do not affect ideal deliberation, and that the evaluation of group discussion is too pessimistic: there are alternative hypotheses to account for his findings, and there are doubts about their external validity. Also, I contend that his evaluation of prediction markets and internet devices is too optimistic. The markets have failed miserably, and the internet is vulnerable to astroturfing by the powerful and wealthy.