There are many reasons why societies run elections. For example, a given society may need
to select its leader (eg, a president), members of a team may need to find an appropriate …

In a typical social choice scenario, agents rank the available alternatives and have to
collectively decide on the best alternative, or a ranking of the alternatives. If there are just …

A committee selection rule (or, multiwinner voting rule) is a map** that takes a collection of
strict preference rankings and a positive integer k as input, and outputs one or more subsets …

We consider approval-based committee voting, ie the setting where each voter approves a
subset of candidates, and these votes are then used to select a fixed-size set of winners …

We consider the following problem: There is a set of items (eg, movies) and a group of
agents (eg, passengers on a plane); each agent has some intrinsic utility for each of the …

Social choice becomes easier on restricted preference domains such as single-peaked,
single-crossing, and Euclidean preferences. Many impossibility theorems disappear, the …

We develop a model of multiwinner elections that combines performance-based measures
of the quality of the committee (such as, eg, Borda scores of the committee members) with …

We study the complexity of (approximate) winner determination under the Monroe and
Chamberlin–Courant multiwinner voting rules, which determine the set of representatives by …

We study the following multiagent variant of the knapsack problem. We are given a set of
items, a set of voters, and a value of the budget; each item is endowed with a cost and each …

Many hard computational social choice problems are known to become tractable when
voters' preferences belong to a restricted domain, such as those of single-peaked or single …