Markus pointed out that Bucklin fails mono add top. Now I see why. If x is ranked second on all of the ballots except the new one, and some other candidate y has exactly 50% first place support, then one ballot of the form x>y will change the Bucklin winner from x to y, because now the collapse to second rank is unnecessary..
So we let's state a special version of participation that Bucklin satisfies: If x wins Bucklin by collapse to level k, then adding a new ballot cannot switch the winner from x to y unless y is ranked above level k or x is ranked below level k. In other words, the new winner has to be ranked relatively high to k or else x has to be ranked relatively low to k in order to change the winner. This seems like a reasonable Participation criterion. It should be enough to overcome the No Show phobia. ---- Election-Methods mailing list - see http://electorama.com/em for list info
