Single-winner voting system

A single-winner voting system is a voting system in which a predetermined constituency elects a single person to some office; such systems contrast generally with proportional representation, in which constituencies are combined to elect several representatives at once. It is also called a single-member district system.

If there is to be only one officeholder, often the case for executive positions such as president, mayor, or governor, single-winner systems are the only option. If there are several officeholders — for instance, for a legislature — there are other voting systems available.

Examples of single-winner systems are plurality voting systems (first-past-the-post), two-round (runoff) systems, instant-runoff voting (IRV), approval voting, range voting, Borda count, and Condorcet methods (such as the Minimax Condorcet, Schulze method, and Ranked Pairs). Of these, plurality and runoff voting are the most commonly used in single-seat constituencies. Their advantages and disadvantages are often conflated with the advantages and disadvantages listed below.

Advantages

Each representative must be a winner

Sometimes voters are in favour of a political party but do not like specific candidates. For example, voters re-elected the Alberta government in 1989 but, because of dissatisfaction with its leadership, the premier and leader of the governing party, Don Getty, lost his seat.

It is often claimed that because each electoral district votes for its own representative, the elected candidate is held accountable to his own voters, thereby helping to prevent incompetent, fraudulent or corrupt behavior by elected candidates. The voters in the electoral district can easily replace him since they have full power over who they want to represent them. In the absence of effective recall legislation, however, the electors must wait until the end of the representative's term. Moreover, it is possible for a winning candidate or government to increase support from one election to the next, but lose the election, or vice-versa. Also, it is generally possible for candidates to be elected if the party regards them as important even if they are fairly unpopular, by moving the candidate to a safe seat which the party is unlikely to lose or by getting a candidate in a safe seat to step down.

On the flip side, in a constituency system, a candidate who is popular nationally may be removed if he is unpopular in his own district. This feature, however, is also present in every proportional system in existence other than a closed party list.

Regionalism

First-past-the-post systems benefit parties that are popular in one geographical region but have little support in other parts of the electorate. In the 2006 Canadian election, the regional Bloc Québécois received 17 percent of the seats (51 seats) with 10 percent of the total votes. In contrast, the New Democratic Party received 9 percent of the seats (29 seats) with 17 percent of the total votes.

Supporters of proportional representation, on the other hand, argue that the single transferable vote system (with small districts, such as 3–5 members in Ireland) retains regionalism and allows proportionality.

Does not give parties excessive power over politicians and voters

A disadvantage of party list systems, one alternative to single-winner systems, is that they give parties excessive power over politicians and voters. Such systems force voters to vote by party rather than by candidate, giving the party structure the power of a middleman.

Preservation of two-party systems

First-past-the-post systems tend to promote two-party systems. Supporters view this as beneficial as governments are typically more stable in two-party systems. First-past-the-post minimizes the influence of third parties and thus arguably keeps out extremists. However, this can also deny fair representation to positive third parties, racial minorities, women, and others.

Disadvantages

Effect on representation

The most commonly expressed disadvantage — perhaps because it is easiest to express and explain — of first-past-the-post is that the winners of the election may not precisely reflect the distribution of votes, with substantial minority vote blocs ignored in their entirety, to the advantage of plurality winners. Thus, substantial bodies of opinion can be rendered irrelevant to the final outcome, and a party can obtain a majority of seats without a majority of the vote. Examples include the United Kingdom general election of 2005 where the new government won 55% of the seats with 35% of the national vote. The disproportionate nature of this system also means that whole regions may have MPs from only one party. The British Conservatives won large majorities of seats in the 1980s on a minority of votes while almost all the Scottish seats were Labour, Liberal or SNP; this disparity created tremendous dissatisfaction in Scotland.

An extreme example of disproportionality arose in Manitoba in the Canadian federal election of 1926. In most Manitoba seats, the non-Conservative parties did not stand candidates against each, resulting in two-way contests between the Conservatives and one other party. The Conservatives received far more votes across the province than any other party, but won no seats.

The usual cause for these disproportionate results is that a party has a large number of votes across the entire territory, but they are spread out across the territory rather than being concentrated in particular constituencies.fact|date=August 2008 Parties with less overall support, but where that support is concentrated in particular constituencies, will win plurality in those constituencies over a party with widely distributed support.

This presents a problem because it encourages parties to focus narrowly on the needs and well-being of specific electoral districts where they can be sure to win seats, rather than be sensitive to the sentiments of voters everywhere.fact|date=August 2008 A further problem is that the party in power often has the ability to determine where the boundaries of constituencies lie: to secure election results, they may use gerrymandering — that is, redistricting to distort election results by enclosing party voters together in one electoral district. Moreover, it can be demonstrated that even the use of non-partisan districting methods — such as computers — to determine constituency boundaries tends to generate results very similar to those produced by a majority party with the power to gerrymander in its favour. [cite book | title = Seats, Votes and the Spatial Organisation of Elections | author = G. Gudgin | coauthors = J. Taylor | year = 1979 | publisher = Methuen & Co. | location = London, England] Conversely, there are cases where there may be no possible way of drawing contiguous boundaries that will allow a minority representation.

afe seats

A safe seat is one in which a plurality of voters support a particular candidate or party so strongly that a majority of votes for that candidate is practically guaranteed in advance of the election. This causes the difficulty that all "other" voters in the constituency can then make no difference to the result, since the winner of the seat is already known in advance. This results in feelings of disenfranchisement, and to abstention.

As an example Gerry Adams of Sinn Féin holds the 4th safest parliamentary seat in Westminster for his West Belfast constituency.

Wasted votes

So-called wasted votes are votes cast for losing candidates or votes cast for winning candidates in excess of the number required for victory. For example, in the UK General Election of 2005, 52% of votes were cast for losing candidates and 18% were excess votes - a total of 70% wasted votes. This is perhaps the most fundamental criticism of single-winner systems when used for a legislature, that a large majority of votes may play no part in determining the outcome. Proportional representation systems attempt to ensure that almost all votes are effective in influencing the result and the number of wasted votes is consequently minimised. The theoretical minimum number of wasted votes under this definition is about 1/(n+1), where n is the number of seats elected by each fixed constituency; thus, a single-winner system has almost 50%, whereas elections for a hundred-member body could have under 1%.

Wipeout and clean sweep results

Since single member constituencies generate a winner's bonus, if not a winner-takes-all situation, the opposition can be left with few if any seats (see above).

It is argued that a weak or absent opposition due to an electoral wipeout is bad for the government. Provincial elections in several Canadian provinces provide suitable examples.

References