Title: Multi-district preference modelling,
Abstract: Generating realistic artificial preference distributions is an important part
of any simulation analysis of electoral systems. While this has been discussed
in some detail in the context of a single electoral district, many electoral
systems of interest are based on multiple 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 number of tunable parameters, is computationally
efficient, and produces "realistic-looking" distributions. We intend to use it
in further studies of electoral systems.