Preferential voting in LiquidFeedback
Often it happens, that you endorse multiple proposals, which are up for election. Some of them might differ only in small details. While with other voting systems, it might happen that such similar proposals divide support between them, which would cause both proposals to fail, LiquidFeedback allows you to vote in favour of many alternative proposals at the same time, while you are still allowed to express your preferences regarding all those proposals you approve and all those approvals you disapprove.
The voter may express his preferences as follows (video):
Drag the most preferred proposal into the green “approval” box. Then choose the next choice, and either drag it into
- the same green box, if you approve both proposals same, and don’t have any preference about them
- between the green approval box and the gray abstention box, if you would only approve the second proposal in case the first proposal doesn’t win
This way a preferential order for all approvals may be determined. It is possible to do the same with disapprovals.
By allowing voters to express their preferences (and taking them into account), voters may approve their second choice without necessarily harming their first choice. As preferences may also be given amongst those proposals you disapprove, voters are not encouraged to approve one proposal to prevent enacting another one.
Technical details:
To determine the winner, the Schulze method is applied to all proposals, which have been voted on. The status-quo is taken into account as an additional “virtual proposal”, where each voter automatically prefers the status-quo to all proposals in “disapproval” boxes, and each voter prefers all proposals in “approval” boxes to the status-quo. The Schulze method creates a ranking (Schulze rank) for all candidates (all proposals and the status-quo), by comparing each candidate with every other candidate. Only proposals which get a better Schulze rank than the status-quo may win. Additional requirements can be configured (e.g. beating the status-quo directly with a simple majority) for a candidate to be eligible as winner. The final winner of the ballot is the eligible candidate with the best Schulze rank.
For a description of the Schulze method, see:
- Wikipedia article about the Schulze method
- Mathematical description of the Schulze method by Markus Schulze (PDF)
For a description of configuration of additional (majority) requirements, see:
