Under a k-approval scoring rule each agent attaches a score of one to his k most preferred alternatives and zero to the other alternatives. The rule assigns the set of alternatives with maximal score. Agents may extend preferences to sets in several ways: they may compare the worst alternatives,...

Effectivity functions for finitely many players and alternatives are considered. It is shown that every monotonic and superadditive effectivity function can be augmented with equalchance lotteries to a finite lottery model---i.e., an effectivity function that preserves the original effectivity...

We analyse the problem of aggregating judgments over multiple issues from the perspective ofefficient aggregation of voters’ private information. While new in judgment aggregation theory,this perspective is familiar in a different body of literature about voting between twoalternatives when...

Nash equilibria with identical supports are compared for bimatrix games that are different with respect to the risk aversion of player 2. For equilibria in 2 by 2-bimatrix games and for equilibria with efficient supports in coordination games it is established for which cases increased risk...

The classical bankruptcy problem (O''Neill, 1982) is extended by assuming that the agents have non-homogenous preferences over several estates. A special case is the one in which there are finitely many estates and the agents have homogenous preferences, i.e., constant utilities, per estate. In...

Two-person noncooperative games with finitely many pure strategies and ordinal preferences over pure outcomes are considered, in which probability distributions resulting from mixed strategies are evaluated according to t-degree stochastic dominance. A t-best reply is a strategy that induces a...

We consider several related set extensions of the core and the anticore of games with transferableutility. An efficient allocation is undominated if it cannot be improved, in a specific way, bysidepayments changing the allocation or the game. The set of all such allocations is called...

We consider bargaining games under the assumption that bargainers are loss averse, i.e. experience disutility from obtaining an outcome lower than some reference point. We follow the approach of Shalev (2002) by imposing the self-supporting condition on a solution. Given a bargaining game, we...

The effect of replacing an agent in a two-person two-state finance economy by a more risk averse agent is studied. It is established under which conditions the other agent benefitsor looses in equilibrium from dealing with a more risk averse agent. If one agent becomes more risk averse, then the...

Single-plateaued preferences generalize single-peaked preferences by allowing for multiple bestelements. These preferences have played an important role in areas such as voting,strategy-proofness andmatching problems. We examine the notion of single-plateauedness in a choice-theoretic...