Can electoral rules be designed to achieve political ideals such as accurate representation of voter preferences and accountable governments? The academic literature commonly divides electoral systems into two types, majoritarian and proportional, and implies a straightforward trade-off by which having more of an ideal that a majoritarian system provides means giving up an equal measure of what proportional representation (PR) delivers. We posit that these trade-offs are better characterized as nonlinear and that one can gain most of the advantages attributed to PR, while sacrificing less of those attributed to majoritarian elections, by maintaining district magnitudes in the low to moderate range. We test this intuition against data from 609 elections in 81 countries between 1945 and 2006. Electoral systems that use low-magnitude multimember districts produce disproportionality indices almost on par with those of pure PR systems while limiting party system fragmentation and producing simpler government coalitions.
An Ideal Electoral System?
I t is widely argued by social scientists of electoral systems that there is no such thing as the ideal electoral system. Although many scholars harbor strong preferences for one type of system over another, in published work and in the teaching of electoral systems it is standard practice to acknowledge the inevitability of trade-offs. If a country wants a highly representative parliament, where the assembly is a microcosm of the pluralism of opinions in society, a proportional representation (PR) system is best. Alternatively, if a country wants the party that wins the most votes in an election to form a stable single-party government, a majoritarian system is best. You have to choose which you care about most: representation or accountable government. You cannot have both, so the mantra goes.A glance at the electoral systems of new democracies, or reforms to electoral systems in established democracies, suggests that electoral engineers regularly