Consensus Formation in Networked Groups

This paper applies the theory of networks to the problem of how agents should assign weights to other agents in the Lehrer-Wagner model for consensus formation. The LehrerWagner theory of consensus is introduced, and the problem of weight assignment is highlighted as one of the open problems for the theory. The paper argues that the application of the theory of networks to the Lehrer-Wagner model constitutes an interesting and fruitful option, among others, for the problem of weight assignment. 1 Social epistemology and consensus models How consensus is formed, that is how situations of disagreement are resolved, is a central topic in social epistemology. Traditionally, epistemologists have been concerned, among other topics, with the problems related to belief formation from an individual perspective, but there is also a very important social dimension to that phenomenon. The idea that group judgment has important epistemic advantages over individual judgment has been treated from numerous perspectives, although the formal treatment of the problem dates back to only a few centuries, with the marquis de Condorcet and the now renown theorem named after him, the Condorcet jury theorem (see List and Goodin 2001; Young 1988). Since then, research in social choice theory, psychology, and social epistemology has highlighted the epistemic advantages as well as disadvantages of group deliberation and group decision making (see Kitcher 1990; Aaken et al. 2004; Goldman 1999). ∗Tilburg Center for Logic and Philosophy of Science, Tilburg University, PO Box 90153, 5000 LE, Tilburg (The Netherlands) http://www.martinicarlo.net [email protected].