Alternative Vote
The Alternative Vote (AV) or Instant-runoff voting (IRV) is a type of ranked preferential voting method. It uses a majority voting rule in single-winner elections where there are more than two candidates. In Australia, where it has seen the widest adoption, it is most commonly referred to as preferential voting in the United Kingdom, it is generally called Alternative Vote (AV); and it is known as ranked-choice voting (RCV) in the United States
Voters in Alternative Vote elections rank the candidates in order of preference. Ballots are initially counted for each voter's top choice. If a candidate has more than half of the vote based on first-choices that candidate wins. If not, then the candidate with the fewest votes is eliminated, and the voters who selected the defeated candidate as a first choice then have their votes added to the totals of their next choice. This process continues until a candidate has more than half of the votes. When the field is reduced to two, it has become an "instant runoff" that allows a comparison of the top two candidates head-to-head. Alternative Vote is not a proportional voting, but a "winner takes all" method as it elects only one winner in an constituency.
The Alternative Vote plus (AV+), or alternative vote top-up, is a semi-proportional voting system. AV+ was devised by the 1998 Jenkins Commission which first proposed the idea as a system that could be used for elections to the Parliament of the United Kingdom .Electoral Reform
As the name suggests, AV+ is an Additional Member System which works in two parts: the 'AV' part and the 'plus' part. As in the alternative vote system, candidates are ranked numerically in order of preference. The important difference is that an additional group of members would be elected through regional party lists to ensure a degree of proportionality; in typical proposals, these members are 15–20% of the whole body. More specifically, each voter would get a second vote to elect a county or regional-level representative from a list of candidates of more than one person per party. The number of votes cast in this vote would decide how many representatives from that county or region would go on to parliament. In systems with an electoral threshold on regional seats, votes are transferred in order of voters' numerical preference until it puts a party above the threshold,
By 2010 FPTP was still in operation. The 1998 Jenkins Report, which was an Independent Commission on the Voting System established by the Labour government a year earlier, recommended replacing the first-past-the-post (FPTP) system used in elections to the Westminster Parliament, with a hybrid system known as alternative vote plus (AV+). But this did not happen.