In the theory of judgment aggregation on logically connected propositions, an important question remains open: Which aggregation rules are manipulable and which are strategy-proof? We define manipulability and strategy-proofness in judgment aggregation, characterize all strategy-proof...

While a large social-choice-theoretic literature discusses the aggregation of individual judgments into collective ones, there is relatively little formal work on the transformation of individual judgments in group deliberation. I develop a model of judgment transformation and prove a baseline...

If a group is modelled as a single Bayesian agent, what should its beliefs be? I propose an axiomatic model that connects group beliefs to beliefs of the group members. The group members may have different information, different prior beliefs and even different domains (algebras) within which...

I examine decentralization through the lens of the local dynamics that it unleashes. The national effects of decentralization are simply the sum of its local-level effects. Hence to understand decentralization we must first understand how local government works. This paper proposes a theory of...

In the framework of judgment aggregation, we assume that some formulas of the agenda are singled out as premisses, and that both Independence (formula-wise aggregation) and Unanimity Preservation hold for them. Whether premiss-based aggregation thus defined is compatible with conclusion-based...

There is a lot of evidence that identity matters for behavior. There is a widespread belief that societies will function better if they manage to establish a common sense of identity among the population. And there are also contemporary fears that this common identity is threatened in several...

In this paper I analyze the effect of the transparency of the decision making process in committees on the decisions that are eventually taken. I focus on committees whose members are motivated by career concerns, so that each member tries to enhance his own reputation. When the decision making...

In response to recent work on the aggregation of individual judgments on logically connected propositions into collective judgments, it is often asked whether judgment aggregation is a special case of Arrowian preference aggregation. We argue the op- posite. After proving a general impossibility...

Empirical evaluation of policies to mitigate climate change has been largely confined to the application of discounted utilitarianism (DU). DU is contro-versial, both due to the conditions through which it is justifed and due to its consequences for climate policies, where the discounting of...

We explain the issue of the decision rule of the EU's Council of Ministers. We outline, in as non-technical fashion as we can, the mathematical theory (due to L S Penrose) that addresses this sort of issue. We assess the decision rule prescribed in the Nice Treaty as well as that included in the...