In a school choice problem each school has a priority ordering over students. These priority orderings depend on criteria such as whether a student lives within walking distance or has a sibling already at the school. We argue that by including just the priority orderings in the problem, and not...

We consider two no-show paradoxes, in which a voter obtains a preferable outcome by abstaining from a vote. One arises when the casting of a ballot that ranks a candidate in first place causes that candidate to lose the election, superseded by a lower-ranked candidate. The other arises when a...

In a school choice problem each school has a priority ordering over the set of students. These priority orderings depend on criteria such as whether a student lives within walking distance or has a sibling already at the school. I argue that by including just the priority orderings in the...

In the random assignment problem, there is a set of agents and a set of the same number of indivisible objects. Each agent has a preference ordering over the objects. We seek a method of assigning one object to each agent, using some randomisation to achieve fairness. The central solutions are...

We consider methods of electing a fixed number of candidates, greater than one, by approval ballot. We define a representativeness property and a Pareto property and show that these jointly imply manipulability.

We consider two no-show paradoxes, in which a voter obtains a preferable outcome by abstaining from a vote. One arises when the casting of a ballot that ranks a candidate in first causes that candidate to lose the election. The other arises when a ballot that ranks a candidate in last causes...

In an important article on collective choice with dichotomous preferences, Bogomolnaia et al. (2005) propose a fairness criterion called fair welfare share. We argue that this criterion permits mechanisms that are not fair and we propose an alternative fairness concept called proportional...