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STV - Overview
Political scientists have long advocated the Single Transferable Vote (STV) as one of the most attractive electoral systems. However, its use for national parliamentary elections has been limited to a few cases - Ireland since 1921 (see Ireland: The Archetypal Single Transferable Vote System), Malta since 1947 (see Malta: STV With Some Twists), and once in Estonia in 1990. It is also used in Australia for elections to the Tasmanian House of Assembly, the Australian Capital Territory Legislative Assembly, and the federal Senate (see The Alternative Vote in Australia); and in Northern Ireland local elections.
In the nineteenth century, Thomas Hare in Britain and Carl Andru in Denmark independently invented the core principles of the system. STV uses multi-member districts, with voters ranking candidates in order of preference on the ballot paper in the same manner as the Alternative Vote (see Alternative Vote). In most cases this preference marking is optional, and voters are not required to rank-order all candidates; if they wish they can mark only one. After the total number of first-preference votes are counted, the count then begins by establishing the "quota" of votes required for the election of a single candidate. The quota is calculated by the simple formula: Quota = (votes/seats + 1) + 1
The first stage of the count is to ascertain the total number of first-preference votes for each candidate. Any candidate who has more first preferences than the quota is immediately elected. If no-one has achieved the quota, the candidate with the lowest number of first preferences is eliminated, with his or her second preferences being redistributed to the candidates left in the race. At the same time, the surplus votes of elected candidates (i.e., those votes above the quota) are redistributed according to the second preferences on the ballot papers. For fairness, all the candidate's ballot papers are redistributed, but each at a fractional percentage of one vote, so that the total redistributed vote equals the candidate's surplus (except in the Republic of Ireland, which uses a weighted sample). If a candidate had 100 votes, for example, and their surplus was ten votes, then each ballot paper would be redistributed at the value of 1/10th of a vote. This process continues until all seats for the constituency are filled.
As a mechanism for choosing representatives, the Single Transferable Vote (STV) is perhaps the most sophisticated of all electoral systems, allowing for choice between parties and between candidates within parties. The final results also retain a fair degree of proportionality, and the fact that in most actual examples of STV the multi-member districts are relatively small means that an important geographical link between voter and representative is retained.
Furthermore, voters can influence the composition of post-election coalitions, as has been the case in Ireland, and the system provides incentives for inter-party accommodation through the reciprocal exchange of preferences. STV also provides a better chance for the election of popular independent candidates than List PR, because voters are choosing between candidates, rather than between parties (although a party-list option can be added to an STV election; this is done for the Australian Senate - see The Alternative Vote in Australia).
The Single Transferable Vote (STV) is often criticized on the grounds that preference voting is unfamiliar in many societies, and demands, at the very least, a degree of literacy and numeracy. The intricacies of an STV count are themselves quite complex, which is also seen as being a drawback.
STV also carries the disadvantages of all parliaments elected by PR methods, such as under certain circumstances increasing the power of small minority parties. Moreover, at times the system, unlike straight List PR, can provide pressures for political parties to fragment internally, because at election-time members of the same party are effectively competing against each other, as well as against the opposition, for votes.
Many of these criticisms have, however, proved to be little trouble in practice. STV elections in Ireland (see Ireland: The Archetypal Single Transferable Vote System), Malta (see Malta: STV With Some Twists) and Tasmania (see The Alternative Vote in Australia) have all tended to produce relatively stable, legitimate governments comprised of one or two main parties.
Current System FPTP Advantages
First Past the Post (FPTP), like other plurality-majority electoral systems, is defended primarily on the grounds of simplicity and its tendency to produce representatives beholden to defined geographic areas. The most often cited advantages of FPTP are that:
It provides a clear cut choice for voters between two main parties. The built-in disadvantages faced by third and fragmented minority parties under FPTP in many cases makes the party system gravitate towards a party of the "left" and a party of the "right", alternating in power. Third parties often wither away, and almost never reach a threshold of popular support where their national vote achieves a comparable percentage of parliamentary seats.
It gives rise to single party governments. The "seat bonuses" for the largest party common under FPTP (i.e., where one party wins, for example, 45 percent of the national vote but 55 percent of the seats) means that coalition governments are the exception rather than the rule. This state of affairs is praised for providing cabinets unshackled from the restraints of having to bargain with a minority coalition partner.
It gives rise to a coherent parliamentary opposition. In theory, the flip side of a strong single-party government is that the opposition is also given enough seats to perform a critical checking role, and present itself as a realistic alternative to the government of the day.
It benefits broadly-based political parties. In severely ethnically or regionally-divided societies, FPTP is praised for encouraging political parties to be "broad churches", encompassing many elements of society, particularly when there are only two major parties and many different societal groups. These parties can then field a diverse array of candidates for election. In FPTP Malaysia, for example, the governing coalition is a broad-based movement, and fields Chinese candidates in Malay areas and vice versa.
It excludes extremist parties from parliamentary representation. Unless an extremist minority party's electoral support is geographically concentrated, it is unlikely to win any seats under FPTP. This contrasts with the situation under straight PR systems, where a fraction of one per cent of the national vote can ensure parliamentary representation.
It retains the link between constituents and their Member of Parliament (MP). Perhaps the most often quoted advantage of FPTP systems is that they give rise to a parliament of geographical representatives: MPs represent defined areas of cities, towns, or regions rather than just party labels. Many proponents of FPTP argue that true representative accountability depends upon the voters of one area knowing who their own representative is, and having the ability to re-elect, or throw them out, at election time. Some analysts have argued that this "geographic accountability" is particularly important in agrarian societies and developing countries (see Holding the Government and Representatives Accountable).
It allows voters to choose between people, rather than just between parties. At the same time, voters can assess the performance of individual candidates, rather than just having to accept a list of candidates presented by a party, as can happen under some List PR electoral systems.
It gives a chance for popular independent candidates to be elected. This is particularly important in developing party systems, where politics revolves more around extended family ties, clan, or kinship, and is not based on strong party-political organizations.
Finally, FPTP systems are particularly praised for being simple to use and understand. A valid vote requires only one mark beside the name or symbol of one candidate, and the number of candidates on the ballot paper is usually small, making the count easy to administer for electoral officials.
Current System FPTP Disadvantages
Excluding Minority Parties from Fair Representation
Here we take the word "fair" to mean that a party which wins approximately ten percent of the votes should win approximately ten percent of the parliamentary seats. In the 1983 British general election, the Liberal-Social Democratic Party Alliance won twenty-five percent of the votes, but only three percent of the seats. In the 1981 New Zealand election the Social Credit Party won twenty-one percent of the vote, but only two percent of the seats. In the 1989 Botswana general election the Botswana National Front won twenty-seven percent of the votes, but only nine percent of the seats. This pattern is repeated time and time again under FPTP (see UK: Electoral System Experimentation in Cradle of FPTP and New Zealand: A Westminster Democracy Switches to PR).
Excluding Minorities from Fair Representation
As a rule, under FPTP, parties put up the most broadly acceptable candidate in a particular district so as to avoid alienating the majority of electors. Thus it is rare, for example, for a black candidate to be given a major party's nomination in a majority white district in Britain or the USA. There is strong evidence that ethnic and racial minorities across the world are far less likely to be represented in parliaments elected by FPTP. In consequence, if voting behaviour does dovetail with ethnic divisions, then the exclusion from parliamentary representation of ethnic minority group members can be destabilizing for the political system as a whole (see US: Ethnic Minorities and Single-Member Districts).
Excluding Women from Parliament
The "most broadly acceptable candidate" syndrome also affects the ability of women to be elected to parliamentary office, because they are often less likely to be selected as candidates by male-dominated party structures. Evidence across the world suggests that women are less likely to be elected to parliament under plurality-majority systems than under PR ones. The Inter-Parliamentary Union's annual study of "Women in Parliament" in 1995 found that on average women made up eleven percent of the parliamentarians in established democracies using FPTP, but the figure almost doubled to twenty percent in those countries using some form of Proportional Representation. This pattern has been mirrored in new democracies, especially in Africa.
Encouraging the Development of Ethnic Parties
In some situations, FPTP can encourage parties to base their campaigns and policy platforms on hostile conceptions of clan, ethnicity, race, or regionalism. In the Malawi multi-party elections of 1994, a history of colonial rule, missionary activity, and Hastings Banda's "Chewa-ization" of national culture combined to plant the seeds of regional conflict which both dovetailed with, and cut across, pre-conceived ethnic boundaries. The South voted for the United Democratic Front of Bakili Muluzi, the Centre for the Malawi Congress Party of Hastings Banda, and the North for the Alliance for Democracy led by Chakufwa Chihana. There was no incentive for parties to make appeals outside their home region and cultural-political base.
Exaggerating "Regional Fiefdoms"
This is where one party wins all the seats in a province or district. In some situations, FPTP tends to create regions where one party, through winning a majority of votes in the region, wins all, or nearly all, of the parliamentary seats. This both excludes regional minorities from representation and reinforces the perception the politics is a battleground defined by who you are and where you live, rather than what you believe in. This has long been put forward as an argument against FPTP in Canada (see The Canadian Electoral System: A Case Study).
Leaving a Large Number of "Wasted Votes"
Votes which do not go towards the election of any candidate are often referred to as 'wasted votes.' Related to "regional fiefdoms" above is the prevalence of wasted votes, when minority party supporters begin to feel that they have no realistic hope of ever electing a candidate of their choice. This can be a particular danger in nascent democracies, where alienation from the political system increases the likelihood that extremists will be able to mobilize anti-system movements.
Being Unresponsive to Changes in Public Opinion
A pattern of geographically-concentrated electoral support in a country means that one party can maintain exclusive executive control in the face of a substantial drop in popular support. In some democracies under FPTP, a fall from sixty percent to forty percent of a party's popular vote nationally, may represent a fall from eighty percent to sixty percent in the number of seats held, which does not affect its overall dominant position. Unless seats are highly competitive, the system can be insensitive to swings in public opinion.
Open to the Manipulation of Electoral Boundaries
Any system with single-member districts is susceptible to boundary manipulation, such as unfair gerrymandering or malapportionment of district boundaries (see Boundary Delimitation). This was particularly apparent in the Kenyan elections of 1993 when huge disparities between the sizes of electoral districts - the largest had 23 times the number of voters as the smallest - contributed to the ruling Kenyan African National Union party's winning a large parliamentary majority with only thirty percent of the popular vote.