Contextual Determinants of Electoral System Choice - Ã bo Akademi

Ware (1991: 66) point out that there are three basic dimensions to consider as forthe constituency structure. Are there on the whole any constituencies? On whatbasis are the constituencies organized? Are the constituencies single-member ormulti-member? Most countries are divided into constituencies but the electionsmay also be conducted ‘at large’, which means that the whole country is one singleconstituency. The constituencies are usually defined territorially, but may also bedefined by population groups.Plurality and majority systems mostly use single-member districts, whereas PRrequires a minimum of two seats per district. Within PR systems, however, thenumber of seats varies a lot between countries and between constituencies withincountries. In these countries, the district magnitude is measured by the arithmeticmean of the number of representatives to be elected in each constituency. Theremay also be two or even more district levels. In addition to the nominal districtlevel, there may be a national district superimposed on the lower-level districts. InRae’s terminology, this phenomenon is called ‘complex districting’ (1967: 124).The district magnitude is closely related to proportionality. When more seats arebeing allocated in one constituency, the possibility of allocating seat shares inaccordance with vote shares equally increases. Several studies have proved thatamong the basic characteristics of electoral systems, the district magnitude has thestrongest effect on the overall proportionality of election results (Gallagher 1991:33-51; Jones 1993: 64-66; Lijphart 1994b; Sartori 1986: 53; Taagepera andShugart 1989b: 112-125).2.1.3 Electoral FormulaThe electoral formula determines how votes are translated into seats. There are,broadly speaking, three methods by which votes can be allocated to seats. Seatscan be allocated to a candidate or a party winning a plurality of the vote, a majorityof the vote, or proportionally among the competitors. In this manner, one maydistinguish between plurality formulas, majority formulas and proportionalformulas. In addition, some electoral systems combine the proportional formulawith the plurality or the majority formula in one election. These are called mixedelectoral systems. Despite the large range of voting procedures, all electoralformulas constitute subtypes of these four categories. This study makes use of thetraditional approach in classifying electoral systems, i.e. according to electoral15