Weak defensive strategy criterion
The weak defensive strategy criterion is a voting system criterion, used to objectively compare voting systems. The criterion states:
If a majority prefers one particular candidate to another, then they should have a way of voting that will ensure that the other cannot win, without any member of that majority reversing a preference for one candidate over another.
Complying methods
Majority-choice approval, cloneproof Schwartz Sequential Dropping and approval methods comply with the weak defensive strategy criterion, while Range voting, Borda count, plurality voting, and instant-runoff voting do not comply.
Commentary
WDSC is identical to the Strong Defensive Strategy criterion (SDSC), except that the phrase "or falsely voting two candidates equal" is removed from the end. That difference allows the approval method to comply.
Some parts of this article are derived with permission from text at http://electionmethods.org
External links
Categories: Voting system criteria