The quest to foretell the future is omnipresent in human affairs. A potential solution to this epistemological conundrum has emerged through mass collaboration. Motored by the Internet, prediction markets allow a multitude of individuals to assume a stake in a security whose value is tied to a future event. The resulting prices offer a continuously updated probability estimate of the event actually taking place. This paper gives a survey of prediction markets, their history, mechanics, uses, and theoretical foundation. We also (...) review the literature surrounding their efficacy. Though there are shortcomings with prediction markets, as well as practical constraints, they hold out the prospect of improving the quality of organizational decisions and increasing the level of participation in the deliberative process. We also note that lessons can be drawn from these markets to guide the epistemological practices of disciplines and inquiries in which empirical methods are difficult to apply. (shrink)

Decision-making typically requires judgments about causal relations: we need to know the causal effects of our actions and the causal relevance of various environmental factors. We investigate how several individuals' causal judgments can be aggregated into collective causal judgments. First, we consider the aggregation of causal judgments via the aggregation of probabilistic judgments, and identify the limitations of this approach. We then explore the possibility of aggregating causal judgments independently of probabilistic ones. Formally, we introduce the problem of causal-network aggregation. (...) Finally, we revisit the aggregation of probabilistic judgments when this is constrained by prior aggregation of qualitative causal judgments. (shrink)

This paper offers a comparison of three different kinds of collective attitudes: aggregate, common, and corporate attitudes. They differ not only in their relationship to individual attitudes—e.g., whether they are “reducible” to individual attitudes—but also in the roles they play in relation to the collectives to which they are ascribed. The failure to distinguish them can lead to confusion, in informal talk as well as in the social sciences. So, the paper’s message is an appeal for disambiguation.

This article criticizes the attempts by Bas van Fraassen and Michael Friedman to address the challenge to rationality posed by the Kuhnian analysis of scientific revolutions. In the paper, I argue that van Fraassen's solution, which invokes a Sartrean theory of emotions to account for radical change, does not amount to justifying rationally the advancement of science but, rather, despite his protestations to the contrary, is an explanation of how change is effected. Friedman's approach, which appeals to philosophical developments at (...) a meta-theoretical level, does not really address the problem of rationality as posed by Kuhn's work. Instead of showing how, despite revolutions, scientific development is, indeed, rational, he gives a transcendental account of rational scientific progress. (shrink)

How can democratic governments be relied upon to achieve adequate political knowledge when they turn over their authority to those of no epistemic distinction whatsoever? This deep and longstanding concern is one that any proponent of epistemic conceptions of democracy must take seriously. While Condorcetian responses have recently attracted substantial interest, they are largely undermined by a fundamental neglect of agenda-setting. I argue that the apparent intractability of the problem of epistemic adequacy in democracy stems in large part from a (...) failure to appreciate the social character of political knowledge. A social point of view brings into focus a number of vital factors that bear on our understanding of democratic epistemology and our assessment of its prospects: the essential role of inclusive deliberation, the public's agenda-setting function, institutional provisions for policy feedback, the independence of expert communities, and the knowledge-pooling powers of markets. (shrink)

Condorcet's classic jury theorem shows that when the members of a group have noisy but independent information about what is best for the group as a whole, majority decisions tend to outperform dictatorial ones. When voting is supplemented by communication, however, the resulting interdependencies between decision-makers can strengthen or undermine this effect: they can facilitate information pooling, but also amplify errors. We consider an intriguing non-human case of independent information pooling combined with communication: the case of nest-site choice by honey (...) bee swarms. It is empirically well-documented that when there are different nest sites that vary in quality, the bees usually choose the best one. We develop a new agent-based model of the bees’ decision process and show that its remarkable reliability stems from a particular interplay of independence and interdependence between the bees. (shrink)