4 ms·

My decision to vote either 0/0/1 or 0/1/1 is explicitly to prevent my desire for B over A from causing B to win when C might have a chance. Whenever you have to

• lmkg 14y ago
  Approval voting is immune to a particular definition of tactical voting, which is somewhat weaker than the traditional one. Which isn't perfect, but it's better than most other methods can offer. Most traditional voting methods are preference systems: You take your N candidates and rank them from 1 to N. Every voter is assumed to have a "ground truth" preference of ranking. Tactical voting means that a rational voter may sometimes be encouraged to vote with a ranking other than their true preference. The weaker criteria that approval voting satisfies is this: A rational voter can always make a rational vote by writing down their true preference ranking in order, drawing a line, and approving everyone above that line. In other words, there is no situation where a rational voter would want to vote A > B when their true preference is B > A. This is a significant bound on the effects of tactical voting. As you correctly point out, the rationally optimal place to draw that line can be tactical. Nonetheless, there is a strong argument that this is "less tactical" than many other systems allow.