Contextual Determinants of Electoral System Choice - Ã bo Akademi

test, the association between regional diffusion and electoral system choice duringthe fourth period is significant at the 0.05 level, indicating that the adoption ofmixed systems and especially proportional systems are results of regionaldiffusion.Seven federal countries adopted electoral systems during the fourth period. Noparticular pattern is observed. The same conclusion applies to electoral systemchoice with respect to chamber structure. 58 cases are related to unicameralsystems, whereas 38 cases are related to bicameral systems. The frequency ofunicameralism is higher in all categories of electoral systems.To sum up, colonial legacy and regional influence explain approximately half of allelectoral system choices during the first period. Seven electoral systems wereinherited, whereas twelve electoral systems were the result of imitatingneighboring countries. Especially proportional systems were subjected to regionaldiffusion. The combination of bicameralism and either plurality or mixed systemswas very common at the middle of the twentieth century. All majority systems, onthe other hand, were adopted in unicameral countries. The rational perspectivedoes not explain electoral system choice during the first two epochs. Concerningcultural diversity, however, there is a clear pattern during the second period:almost all countries characterized by medium-sized or high level of fragmentationadopted inappropriate electoral systems. However, colonial legacy explains thisrelationship. More than half of all systems were inherited from the colonialpowers, mainly Britain and France. Another 19 choices were associated withregional diffusion. Almost every adopted plurality system was a consequence ofeither colonial or regional diffusion.Party system transformation preceded the adoption of mixed or proportionalsystems in seven cases during the third period. As for the rest, diffusion was theprominent factor. 13 electoral systems were inherited from the colonial powers,mostly the United Kingdom. 19 choices, foremost plurality systems, wereinfluenced by neighboring countries. The rational perspective became a relevantexplanatory model during the fourth period. Mixed systems were adopted primarilyin large countries, the use of single-member districts being regarded as the crucialfactor. 24 party system transformations were succeeded by changes frommajoritarian to mixed or proportional systems. Colonial legacy did no longer play192