Multiple-choice Referendums
A referendum usually offers the electorate only two choices, either to accept or reject a proposal, but this need not necessarily be the case. In Switzerland, for example, multiple choice referendums are common; two multiple choice referendums held in Sweden, in 1957 and 1980, offered voters a choice of three options; and in 1977 a referendum held in Australia to determine a new national anthem was held in which voters were presented with four choices.
A multiple choice referendum poses the problem of how the result is to be determined if no single option receives the support of an absolute majority (more than half) of voters. This can be resolved by applying voting systems designed for single winner elections to a multiple-choice referendum.
Swiss referendums get around this problem by offering a separate vote on each of the multiple options as well as an additional decision about which of the multiple options should be preferred. In the Swedish case, in both referendums the 'winning' option was chosen by the Single Member Plurality ("first past the post") system. In other words the winning option was deemed to be that supported by a plurality, rather than an absolute majority, of voters. In the 1977 Australian referendum the winner was chosen by the system of preferential instant-runoff voting.
Although California does not have deliberate multiple-choice referendums in the Swiss or Swedish sense (in which only one of several counter-propositions can be victorious, and the losing proposals are wholly null and void), it does have so many yes-or-no referendums at each Election Day that the State's Constitution provides a method for resolving inadvertent conflicts when two or more inconsistent propositions are passed on the same day. This is a de facto form of Approval Voting - i.e., the proposition with the most "yes" votes prevails over the others to the extent of any conflict.
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