Quantum decision theory (QDT) is a recently developed theory of decision making based on the mathematics of Hilbert spaces, a framework known in physics for its application to quantum mechanics. This framework formalizes the concept of uncertainty and other effects that are particularly manifest...

Experts often disagree. A decision-maker may be averse to such expert disagreement. Existing models of aversion to expert disagreement rest on ambiguity-averse preferences adopting a unanimity principle: If all experts consider one choice better than another, so should the decision-maker. Such...

We consider the allotment problems of homogeneous indivisible objects among agents with single-peaked and risk-averse von Neumann-Morgenstern expected utility functions. We establish that the rule satisfies coalitional strategy-proofness, same-sideness, and strong symmetry if and only if it is...

We consider a committee facing a binary decision under uncertainty. Each member holds some private information. Members may have different preferences and initial beliefs, but they all agree which decision should be taken in each of the two states of the world. We characterize the optimal...

Most monetary policy committees decide on interest rates using a simple majority voting rule. Given the inherent heterogeneity of committee members, this voting rule is suboptimal in terms of the quality of the interest rate decision, but popular for other (political) reasons. We show that a...

Cerreia-Vioglio, Ghirardato, Maccheroni, Marinacci and Siniscalchi (Economic Theory, 48:341-375, 2011) have recently axiomatised preferences in the presence of ambiguity as Monotonic Bernoullian Archimedean (MBA) preferences. We investigate the problem of Arrovian aggregation of MBA preferences...

We investigate experimentally whether collective choice matters for individual attitudes to ambiguity. We consider a two-urn Ellsberg experiment: one urn offers a 45% chance of winning a fixed monetary prize, the other an ambiguous chance. Participants choose either individually or in groups of...

We study a vote buying setup where a committee votes on a proposal important to the vote buyer. We characterize the cheapest combination of bribes that guarantees the proposal's passing in different voting environments. We find that for both simultaneous and sequential votes, the vote buyer...

We consider collective decision problems where some agents have private information about alternatives and others don't. Voting takes place under strategy-proof rules. Prior to voting, informed agents may or may not disclose their private information, thus eventually influencing the preferences...

In this paper we provide an axiomatic characterization of the maxmin choice correspondence for a decision maker who has state-dependent preferences (represented by a linear order) over the set of alternatives