In
social choice theory
Social choice theory or social choice is a theoretical framework for analysis of combining individual opinions, preferences, interests, or welfares to reach a ''collective decision'' or ''social welfare'' in some sense.Amartya Sen (2008). "Soci ...
, Neutrality is a basic requirement of a social choice rule. It says that the rule does not discriminate apriori between different candidates. In other words, if the vector of candidates is permuted arbitrarily, then the returned result is permuted in the same way.
[{{Cite book, last=Felix Brandt, chapter-url=https://books.google.com/books?id=0qY8DwAAQBAJ&q=multiwinner++voting+a+new+challenge&pg=PA27, title=Trends in Computational Social Choice, date=2017-10-26, publisher=Lulu.com, isbn=978-1-326-91209-3, editor-last=Endriss, editor-first=Ulle, language=en, chapter=Roling the Dice: Recent Results in Probabilistic Social Choice]
Neutral rules
Most voting rules are neutral. For example,
plurality voting
Plurality voting refers to electoral systems in which a candidate, or candidates, who poll more than any other counterpart (that is, receive a plurality), are elected. In systems based on single-member districts, it elects just one member per ...
is neutral, since only counts the number of votes received by each candidate, without giving an a-priori preference to any candidate. Similarly, the
utilitarian rule
In social choice and operations research, the utilitarian rule (also called the max-sum rule) is a rule saying that, among all possible alternatives, society should pick the alternative which maximizes the ''sum of the utilities'' of all individual ...
and
egalitarian rule In social choice and operations research, the egalitarian rule (also called the max-min rule or the Rawlsian rule) is a rule saying that, among all possible alternatives, society should pick the alternative which maximizes the ''minimum utility'' of ...
are both neutral, since the only consider the utility given to each candidate, regardless of the candidate's name or index.
Non-neutral rules
An example of a ''non''-neutral rule is a rule which says that, in case of a tie, the alternative ''X'' is selected. This is particularly prominent in cases in which ''X'' is the
status quo
is a Latin phrase meaning the existing state of affairs, particularly with regard to social, political, religious or military issues. In the sociological sense, the ''status quo'' refers to the current state of social structure and/or values. W ...
option; it is often preferred to keep the status quo unless there is a strict majority against it.
See also
*
Anonymity (social choice) - a related requirement, saying that the rule does not discriminate apriori between different ''voters''.
References
Social choice theory