Divisor-Based Biproportional Apportionment in Electoral Systems: A Real-Life Benchmark Study

Sebastian Maier, Petur Zachariassen, Martin Zachariasen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review


Biproportional apportionment methods provide two-way proportionality in electoral systems where the electoral region is subdivided into electoral districts. The problem is to assign integral values to the elements of a matrix that are proportional to a given input matrix, and such that a set of row- and column-sum requirements are fulfilled. In a divisor-based method for biproportional apportionment, the problem is solved by computing appropriate row and column divisors, and by rounding the quotients. We present a comprehensive experimental evaluation of divisor-based biproportional apportionment in an electoral system context. By performing experiments on real-life benchmark instances (election data with multimember districts), we evaluate the general quality of divisor-based apportionments with respect to, e.g., deviation from quota, reversal orderings, and occurrences of ties. For example, we studied the frequency in which a party with a higher vote count in a district ended up with fewer seats in that district.
TidsskriftManagement Science
Udgave nummer2
Sider (fra-til)373-387
StatusUdgivet - 2010
Udgivet eksterntJa


Dyk ned i forskningsemnerne om 'Divisor-Based Biproportional Apportionment in Electoral Systems: A Real-Life Benchmark Study'. Sammen danner de et unikt fingeraftryk.