The concept of program equilibrium, introduced by Howard (Theory and Decision 24(3):203–213, <CitationRef CitationID="CR13">1988</CitationRef>) and further formalised by Tennenholtz (Game Econ Behav 49:363–373, <CitationRef CitationID="CR19">2004</CitationRef>), represents one of the most ingenious and potentially far-reaching applications of ideas from computer science in game...</citationref></citationref>

<Para ID="Par1">An alternative is said to be a Condorcet winner of an election if it is preferred to any other alternative by a majority of voters. While this is a very attractive solution concept, many elections do not have a Condorcet winner. In this paper, we propose a set-valued relaxation of this concept,...</para>

When rational but myopic agents negotiate over the exchange of indivisible resources, any restriction to the negotiation protocol may prevent the system from converging to a socially optimal allocation in the general case. This paper addresses this issue by analysing how the confinement to...

In many practical contexts where a number of agents have to find a common decision, the votes do not come all together at the same time. In such situations, we may want to preprocess the information given by the subelectorate (consisting of the voters who have expressed their votes) so as to...

Voting on multiple related issues is an important and difficult problem. The key difficulty is that the number of alternatives is exponential in the number of issues, and hence it is infeasible for the agents to rank all the alternatives. A simple approach is to vote on the issues one at a...

In voting contexts, some new candidates may show up in the course of the process. In this case, we may want to determine which of the initial candidates are possible winners, given that a fixed number k of new candidates will be added. We give a computational study of this problem, focusing on...

In many practical contexts where a number of agents have to find a common decision, the votes do not come all together at the same time. In such situations, we may want to preprocess the information given by the subelectorate (consisting of the voters who have expressed their votes) so as to...

Voting on multiple related issues is an important and difficult problem. The key difficulty is that the number of alternatives is exponential in the number of issues, and hence it is infeasible for the agents to rank all the alternatives. A simple approach is to vote on the issues one at a...

When rational but myopic agents negotiate over the exchange of indivisible resources, any restriction to the negotiation protocol may prevent the system from converging to a socially optimal allocation in the general case. This paper addresses this issue by analysing how the confinement to...

In many real-world group decision making problems, the set of alternatives is a Cartesian product of finite value domains for each of a given set of variables (or issues). Dealing with such domains leads to the following well-known dilemma: either ask the voters to vote separately on each issue,...