Political Districting Problem: Literature Review and Discussion with regard to Federal Elections in Germany Sebastian Goderbauer1;2 and Jeff Winandy1 1 Lehrstuhl für Operations Research, RWTH Aachen University, Kackertstraße 7, 52072 Aachen, Germany 2 Lehrstuhl II für Mathematik, RWTH Aachen University, Pontdriesch 10-12, 52062 Aachen, Germany
[email protected] October 24, 2018 Abstract. Electoral districts have great significance for many demo- cratic parliamentary elections. Voters of each district elect a number of representatives into parliament. The districts form a partition of the electoral territory, meaning each part of the territory and population is represented. The problem of partitioning a territory into a given number of electoral districts, meeting various criteria specified by laws, is known as the Political Districting Problem. In this paper, we review solution ap- proaches proposed in the literature and survey districting software, which provides assistance with interactive districting by hand or even decision support in the form of optimization-based automated districting. As a specific application, we consider the Political Districting Problem for the federal elections in Germany. Regarding the present requirements and objectives, we discuss and examine the applicability of the approaches mentioned in the literature to this specific German Political Districting Problem. Keywords: Redistricting; Electoral District Design; Solution Approaches; Literature Survey; (Re)Districting Software; OR in Government 1 Introduction In preparation for an upcoming parliamentary election, a country is generally subdivided into electoral districts. These districts are of fundamental importance in democratic elections, because the voters of each district elect a number of representatives into parliament. In general, the number of seats staffed by an electoral district is determined a priori in line with the district’s population.