SPACE voting: Difference between revisions
add Proportional and Delegated categories
imported>Homunq (Created page with "SPACE voting is a summable proportional, optionally-delegated voting method for nonpartisan elections such as a city council. Essentially, it works as partially-delegated STV....") |
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If they choose exactly one candidate, and grade any others, their vote is undelegated; that is, converted to an STV ballot using the tally of voters who chose the same candidate. Say that of the 1000 votes for X, there are 700 which accept Y, 500 which accept Z, 400 which accept W, and 100 which accept V. 700+500+400+100=1700 approvals, which is greater than the total number of votes involved by 700, so there are 700 excess approvals. 100 filled-in ballots which include all 4 secondary candidates would account for 300 excess approvals, leaving 400; 200 more filled-in ballots which include 3 candidates would account for the remaining 400 excess approvals. So we have:
100: X>VWYZ (divide equally among remaining candidates)
200: X>WYZ (ditto)
700-300=400: X>Y▼
Total filled in: 100+200+400+200+100=1000.
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This rule does not unfairly punish voters who choose a minor candidate, since their votes are still eventually transferred.
== Strategic issues ==
=== Favorite betrayal? ===
Say that your preference is A>BC; that A, B, and C have all endorsed each other and nobody else; and that D has endorsed C and E. Should you vote for your true favorite A, or compromise by voting for C? If you do the latter, you may cause C's tally to pass E's, so that C gets D's delegated votes before E does. So a favorite betrayal strategy may work in this case.
However, if A has any chance of winning, then it's unlikely this strategy makes a difference, because there are likely enough votes from A for C to win a seat without needing D's votes. So the only time this strategy is really worth it is if the cost, in terms of reduced chances of electing A, is negligible anyway.
=== False-flag? ===
In theory, it could in some cases be strategic to vote for a candidate you did not like at all and then accept several candidates you did like. If the first candidate you voted for was eliminated, your vote could carry along a fraction of an extra vote to the candidates you did like. However, the risk would be that your vote would go to a candidate you did not like. In general, this is not likely to be a viable strategy.
In particular, this strategy could only steal a fraction of the non-delegated votes for a weak candidate — likely a negligible amount. And it would always reduce the initial tally for your true favorite, which could have downsides in various ways.
== Similar methods ==
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[[Proportional 3RD voting]]: an old version of PACE.
[[Category:Proportional voting methods]]
[[Category:Delegated voting methods]]
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