Judgment aggregation in search for the truth

We analyze the problem of aggregating judgments over multiple issues from the perspective of whether aggregate judgments manage to efficiently use all voters' private information. While new in judgment aggregation theory, this perspective is familiar in a different body of literature about voting between two alternatives where voters' disagreements stem from conflicts of information rather than of interest. Combining the two bodies of literature, we consider a simple judgment aggregation problem and model the private information underlying voters' judgments. Assuming that voters share a preference for true collective judgments, we analyze the resulting strategic incentives and determine which voting rules efficiently use all private information. We find that in certain, but not all cases a quota rule should be used, which decides on each issue according to whether the proportion of ‘yes’ votes exceeds a particular quota

Collective economic decisions and the discursive dilemma

Most economic decisions involve judgments. When decisions are taken collectively, various judgment aggregation problems may occur. Here we consider an aggregation problem called the "discursive dilemma", which is characterized by an inconsistency between the aggregate judgment on the premises for a conclusion and the aggregate judgment on the conclusion itself. It thus matter for the decision whether the group uses a premise- or a conclusion-based decisionmaking procedure. The current literature, primarily within jurisprudence, philosophy, and social choice, consider aggregation of qualitative judgments on propositions. Most economic decisions, however, involve quantitative judgments on economic variables. We develop a framework that is suitable for analyzing the relevance of the discursive dilemma for economic decisions. Assuming that decisions are reached either through majority voting or by averaging, we find that the dilemma cannot be ruled out, except under some restrictive assumptions about the relationship between the premise-variables and the conclusion.Collective economic decisions, Judgement aggregation, Inconsistency

Is Specialization Desirable in Committee Decision Making?

Committee decision making is examined in this study focusing on the role assigned to the committee members. In particular, we are concerned about the comparison between committee performance under specialization and non-specialization of the decision makers.framing, project selection, public policy, collective decision making, committee, uncertain dichotomous choice, specialization, simple majority rule

Measuring satisfaction in societies with opinion leaders and mediators

An opinion leader-follower model (OLF) is a two-action collective decision-making model for societies, in which three kinds of actors are considered:Preprin

Social choice theory, game theory, and positive political theory

We consider the relationships between the collective preference and non-cooperative game theory approaches to positive political theory. In particular, we show that an apparently decisive difference between the two approachesthat in sufficiently complex environments (e.g. high-dimensional choice spaces) direct preference aggregation models are incapable of generating any prediction at all, whereas non-cooperative game-theoretic models almost always generate predictionis indeed only an apparent difference. More generally, we argue that when modeling collective decisions there is a fundamental tension between insuring existence of well-defined predictions, a criterion of minimal democracy, and general applicability to complex environments; while any two of the three are compatible under either approach, neither collective preference nor non-cooperative game theory can support models that simultaneously satisfy all three desiderata

The Discursive Dilemma in Monetary Policy

The discursive dilemma implies that the policy decision of a board of policymakers depends on whether the board reaches the decision by voting directly on policy (conclusion-based procedure), or by voting on the premises for the decision (premise-based procedure). We derive results showing when the discursive dilemma may occur, both in a general model and in a standard monetary policy model. When the board aggregates by majority voting, a discursive dilemma can occur if either (i) the relationship between the premise and the decision is non- monotonic, or (ii) if the board members have di¤erent judgments on at least two of the premises. Normatively, a premise-based procedure tends to give better decisions when there is disagreement on parameters of the model.Discursive dilemma; Monetary policy; MPC; Policy boards