Two important factors to be considered when contemplating electoral districting alternatives are: (1) district magnitude and (2) the alignment of electoral district boundaries with existing administrative and/or political boundaries. District magnitude refers to the number of legislative seats assigned to a district[1]. A district can be either a single-member district or a multimember district, where the number of seats may range from two to one hundred or more. Electoral districts can be aligned with administrative divisions—that is, administrative divisions can be used as electoral districts—or electoral districts can be specially drawn with little regard for administrative divisions, usually to meet equal population criteria.
These two factors form a matrix [2]. The first dimension, district magnitude, relates to the issue of single-member versus multimember districts. The second dimension refers to the alignment or nonalignment of electoral districts with administrative or political boundaries.
Most single-member districts fall into the nonalignment category. The districts tend to be artificial pieces of geography that have no meaning outside the electoral context. Some single-member districts, however, particularly those in proportional representation countries, are small, highly distinctive communities. For example, a few small cantons in Switzerland form single-member districts.
Countries with multimember districts often use existing administrative divisions as electoral districts. Each district is assigned the appropriate number of legislative seats for its population, with individual districts having as few as two representatives and most districts having far more than two representatives. These countries usually employ some form of proportional representation. The more artificially constructed multimember districts are found in countries such as Ireland and Malta, which use districts that are uniformly small in magnitude because elections are conducted using the single transferable vote.
More information on the Alignment of
Districts with Administrative Boundaries can be found here.
Notes:
[1] According to Taagepera and Shugart, the term "magnitude" is preferable to "size," because size usually refers to the number of voters in an electoral district or the geographic extent of a district. See Rein Taagerpera and Matthew Soberg Shugart, Seats and Votes: The Effects and Determinants of Electoral Systems (New Haven: Yale University Press, 1989)
[2] Michael Steed, "The Constituency," in Representative of the People? Parliamentarians and Constituencies in Western Democracies, ed. Vernon Bogdanor (Grower Publishing, 1985)
