Multi-district preference modelling

This paper with longtime coauthor Geoffrey Pritchard is an important step toward systematic design of electoral systems.

Abstract: Generating realistic artificial preference distributions is an important part of
any simulation analysis of electoral systems. While this has been discussed in some de-
tail in the context of a single electoral district, many electoral systems of interest are based
on districts. Neither treating preferences between districts as independent nor ignoring
the district structure yields satisfactory results. We present a model based on an extension
of the classic Eggenberger-Pólya urn, in which each district is represented by an urn and
there is correlation between urns. We show in detail that this procedure has a small num-
ber of tunable parameters, is computationally efficient, and produces “realistic-looking”
distributions. We intend to use it in further studies of electoral systems.