We explore to what extent we can propose fixed negotiation rules as well as simple mechanisms (or protocols) that guarantee that political parties can form stable coalition-governments. We analyze the case where three parties can hold office in the form of two-party coalitions. We define the...

We study a problem where a group of voters must decide which candidates are elected from a set of alternatives. The voters’ preferences on the combinations of elected candidates are represented by orderings. We propose a family of restrictions of the domain of separable preferences. These...

We investigate the implications and logical relations between progressivity (a principle of distributive justice) and merging-proofness (a strategic principle) in taxation. By means of two characterization results, we show that these two principles are intimately related, despite their different...

This paper is devoted to the study of claims problems. We identify the family of rules that satisfy strong composition down (robustness with respect to reevaluations of the estate) and consistency (robustness with respect to changes in the set of agents) together. Such a family is the Þxed path...

A jury has to decide the winner of a competition among a group of contestants. All members of the jury know who the deserving winner is, but this contestant is unknown to the planner. The social optimum is that the jury select the deserving winner. Each individual juror may be biased in favor...

We analyze the problem of choosing the w contestants who will win a competition within a group of nw competitors when all jurors commonly observe who are the w best contestants but may be biased. We study conditions on the configuration of the jury so that it is possible to induce the jurors to...

A high court has to decide whether a law is constitutional, un- constitutional, or interpretable. The voting system is runoff. Runoff voting systems can be interpreted both, as social choice functions or as mechanisms. It is known that, for universal domains of preferences, runoff voting systems...

A jury has to choose the winner of a contest. There exists a deserving winner, whose identity is common knowledge among the jurors, but not known by the planner. Jurors may be biased in favor (friend) or against (enemy) some contestants. We study conditions on the confi?guration of the jury so...