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...

It is well known that many social decision procedures are manipulable through strategic behaviour. Typically, the decision procedures considered in the literature are social choice correspondences. In this paper we investigate the problem of constructing a social welfare function that is...

In the literature on social choice and fuzzy preferences, a central question is how to represent the transitivity of a fuzzy binary relation. Arguably the most general way of doing this is to assume a form of transitivity called max-star transitivity. The star operator in this formulation is...

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...

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.