A donkey vote is a ballot cast in an election that uses a preference voting system, where a voter is permitted or required to rank candidates on the ballot paper, and ranks them based on the order they appear on the ballot paper. The voter that votes in this manner is referred to as a donkey voter.
Typically, this involves numbering the candidates in the order they appear on the ballot paper: first preference for the first-listed candidate, second preference for the second-listed candidate, and so on. However, donkey votes can also occur in reverse, such that someone numbers the candidates from the bottom up the ballot paper. In systems where a voter is required to place a number against each candidate for the vote to be valid, the voter may give the first preference to the candidate they prefer, then run all the other numbers donkey fashion.
Donkey votes are most common where preference voting is combined with compulsory voting, such as in Australia, particularly where all candidates must be ranked on the ballot paper. There are different versions of the phenomenon applicable in the Australian House of Representatives, Australian Senate and in the Australian jurisdictions that use the Hare–Clark single transferable vote system.
Donkey votes may occur for several reasons, including voter apathy, protest voting, simplicity on how to vote cards, the complexity of the voting system, or voter ignorance of the voting system rules. Alternatively, what appears as a donkey vote may in fact be a genuine representation of a voter's preferences.
Preferential voting for a single seat is used in elections for the Federal House of Representatives (since 1918), for all mainland State lower houses, and for the Northern Territory Legislative Assembly. It was also used for the Western Australian Legislative Council until 1986, and the Victorian Legislative Council until 2006; it is still used for the Tasmanian Legislative Council. A variant was used for the South Australian Legislative Council before 1973, with two seats per "province" (electoral district) being filled at each election, but by majority-preferential voting, not by proportional representation.