2 research outputs found
Online Approval Committee Elections
Assume candidates need to be selected. The candidates appear over time.
Each time one appears, it must be immediately selected or rejected -- a
decision that is made by a group of individuals through voting. Assume the
voters use approval ballots, i.e., for each candidate they only specify whether
they consider it acceptable or not. This setting can be seen as a voting
variant of choosing secretaries. Our contribution is twofold. (1) We assess
to what extent the committees that are computed online can proportionally
represent the voters. (2) If a prior probability over candidate approvals is
available, we show how to compute committees with maximal expected score
Classification Aggregation without Unanimity
A classification is a surjective mapping from a set of objects to a set of
categories. A classification aggregation function aggregates every vector of
classifications into a single one. We show that every citizen sovereign and
independent classification aggregation function is essentially a dictatorship.
This impossibility implies an earlier result of Maniquet and Mongin (2016), who
show that every unanimous and independent classification aggregation function
is a dictatorship. The relationship between the two impossibilities is
reminiscent to the relationship between Wilson's and Arrow's impossibilities in
preference aggregation. Moreover, while the Maniquet-Mongin impossibility rests
on the existence of at least three categories, we propose an alternative proof
technique that covers the case of two categories, except when the number of
objects is also two. We also identify all independent and unanimous
classification aggregation functions for the case of two categories and two
objects