Electoral Systems and the Delimitation of Constituencies

Publication Date: 
2 Jul 2009

Publication Type:


Recently a number of public officials and commentators have called for a restructuring of the electoral system in Ukraine.  Those advocating change contend that the current proportional representation system, closed list, with a single national constituency, grants too much power to party leaders, leaving politicians to answer to the political elite and not voters at large. Reformers advocate a political system with multiple geographic constituencies to address these problems and improve the quality of Ukrainian governance.

Are there advantages in delimiting constituencies?

Delimiting electoral districts does offer some advantages over maintaining a single nationwide constituency for parliamentary elections. 

First, electoral districts improve the accountability of representatives to their voters.  A major advantage of a districted system is that electoral districts link elected representatives to a smaller, geographically-defined, constituency.  This allows voters to hold specific representatives accountable – voting them out of office if they do not act in accordance to voters’ wishes and returning them to office if they do. 

Second, electoral districts can ensure broader geographic representation in parliament.  Assuming candidates are required to reside in the districts they represent, electoral districts guarantee a level of geographic diversity in the legislative assembly that may not necessarily occur in other systems without such districts.  This generally also means more attention will be accorded to regional issues and to constituency service.

Third, electoral districts would permit the use of an open party list – something that is quite difficult to manage administratively with a single national constituency.  With constituencies in place the number of seats to fill within each district would be more limited than in the case of a single national constituency.  The election ballot would be less cumbersome, and more importantly, the choices would presumably be more meaningful to voters.

But altering the electoral system to include the delimitation of electoral districts has disadvantages associated with it as well.  The most compelling argument against delimitation is that a constituency-based system can produce less than proportional election results.  For example, a party could have a considerable base of support nationwide, yet fail to win a single district contest. This party (and their supporters) would effectively be shut out of the parliament if there is no other method in place to allocate seats to these minority parties.  This can, in fact, be a high cost to pay for a geographic link between constituents and their representatives, especially in an emerging or transitional democracy. 

Another disadvantage associated with electoral districts is that these districts must be redrawn, or distribution of seats reallocated, periodically to reflect shifts in the population.  These processes require sufficient planning and resources to carry out the task effectively.

Electoral systems that delimit constituencies.

Traditionally, electoral systems have been categorized into three groups: (1) plurality systems, (2) majority systems, and (3) proportional representation systems. The most important element that differentiates these electoral systems from one another is the means by which seats in the legislature are allocated: (1) to candidates receiving a plurality of the vote, (2) to candidates obtaining a majority of the vote, and (3) proportionally on the basis of votes cast for political parties or candidates.  A recent addition to these three categories is the mixed electoral system, which combines elements of both proportional representation and plurality or majority voting systems.

Plurality and Majority Systems   The delimitation of electoral districts is most commonly associated with plurality and majority electoral systems.  Both systems tend to rely heavily, if not exclusively, on single-member electoral districts. 

Because of their reliance on single-member districts, the number of seats that a political party receives in these systems depends not only on the proportion of votes it received, but also on where those votes were cast.  Under plurality and majority systems, minority political parties whose supporters are not geographically concentrated usually obtain fewer seats than their proportion of the vote would suggest they are entitled.  This constitutes the primary disadvantage of these systems: larger parties tend to be over-represented in parliament while smaller political parties and minority groups do not fare particularly well under these systems.

The major advantages associated with plurality and majority systems are that (1) they are usually quite simple to understand; (2) they offer voters a clearly identifiable representative (beholden to a specific geographic area) that can be held accountable and can be called on to provide information and services; and (3) they foster one-party government that can, in certain instances, enhance the opportunity for a stable and decisive government.

Proportional Representation Systems   The List Proportional Representation (PR) system is the most common PR system.  Under this system, if electoral districts are employed at all, they are relatively large multimember districts with boundaries that generally correspond to administrative divisions.  To accommodate shifts in population, the number of seats allocated to individual constituencies is varied rather than redrawing the boundaries of the electoral districts. 

List PR requires each party to present a list of candidates to the electorate. Electors vote for a party (or, in the case of an open list, for candidates within a certain party); parties receive seats in proportion to their overall share of the national vote.  This is the system currently employed in Ukraine (closed list) and is widely used in continental Europe, as well as Latin America. 

The strongest argument in favor of PR systems in general is that these systems avoid the anomalous election results of plurality and majority systems and facilitate a more representative legislature.  For many newly emerging and transitional democracies, particularly those that face deep societal divisions, the inclusion of all significant groups in the parliament may be an essential condition for democratic consolidation.  But PR systems do have some decided disadvantages:

  • PR systems often lead to coalition governments, which can lead to legislative gridlock and the inability to carry out coherent policies.
  • Some PR systems do not provide a strong linkage between a representative and his or her electorate. (This is not true of Mixed Member Proportional systems, however – see below.)
  • PR systems offer a platform for small extremist parties (unless a high threshold is set for obtaining a seat in parliament).
  • Some PR systems are criticized for leaving too much power in the hands of senior party officials (for example, a candidate’s position on the party list, and therefore his or her likelihood of success, is often dependent on one or two party leaders).  This is particularly true of a national closed-list PR system.

Mixed Electoral Systems     Mixed electoral systems are becoming increasingly popular.  They are called “mixed” because they employ both party list proportional representation and single-member (or small multimember) electoral districts, usually with plurality or majority vote requirements.  The influence that district configurations have on the outcome of elections is dependent on whether the party list seats are used to correct any distortions in the relationship between votes cast to seats won produced by the single-member districts. 

In countries such as Germany and New Zealand, seats allocated under the party list component of the system are used to compensate for any distortions in the seats-to-votes ratio produced at the electoral district level. For example, if a political party were to win 55% of the total vote cast in a parliamentary election but win only 45% of the constituency seats, compensatory seats would be allocated to the party such that the percentage of seats held by that party would total 55% of the assembly seats overall.  Mixed systems that use party list seats in a compensatory manner are referred to as "Mixed Member Proportional" systems because the election results are proportional to the party votes cast. 

Under the mixed system in place in Ukraine for the 1998 to 2002 parliamentary elections, the 225 party list seats (of the 450-seat legislature) were not used to compensate for any disproportionality arising from elections in the single-member districts.  Instead, seats allocated to the parties under the party list component of the election were simply added to the seats won at the electoral district level.  For example, in the 2002 election, the Social Democratic Party of Ukraine (United) won 5 of the 225 single-member districts. In addition, the party won 6.3% of the national vote, which translated into 19 additional seats after accounting for parties that failed to reach the 4% threshold and using the distributing quota.  These 19 seats, added to their 5 single-member district seats, gave the party 24 seats in the parliament. In this type of mixed system, sometimes called a "parallel" system, the district delimitation process is more important because it can have a more pronounced effect on the partisan composition of the legislature. (Parallel systems are used in, for example, Russia, Georgia, Japan, South Korea, Thailand and the Philippines.)

Conclusion: Reforming the electoral system to include electoral districts.

There is no perfect electoral system – major design criteria often conflict with each other or are even mutually exclusive.  For example, the choice to include electoral districts in the design can affect electoral outcomes dramatically, especially if political party support is not geographically concentrated. The trade-off between representative accountability and proportional representation must be considered carefully.  Serious consideration must be given to prioritizing the criteria that are most important in a given political context. 

Not only should any debate in Ukraine on incorporating districts not be taken lightly, it is a debate and decision that must take place well before the scheduled election if the delimitation process is to be carried out as efficiently, accurately, impartially and transparently as possible.

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