German Approval Voting Polls
The following synopsis of Approval Voting experiments conducted in Germany is described in detail in this PDF.
On 2008 Jan 21, an Approval Voting poll was performed at three voting stations in Messel, Germany, with government approval/cooperation. 1,909 voters participated (72.6% of the voters at those election sites).
In the district elections, the average voter voted for 1.86 candidates out of 8.
In the state elections, the average voter voted for 2.25 parties out of 17.
In the state elections, the Greens went from having 18% as many votes as the first-ranking SPD (in the real election), to having 67% as many votes as the SPD in the Approval Voting election (which was held at the polling site, simultaneously with the real voting).
The author says:
The third and fourth finishers swapped places and the sixth and seventh too, thanks to the change from Plurality to Approval Voting. The Plurality results were 45.9%, 37.9%, 4.5%, 6.0%, 3.4%, 0.8%, 1.1%, 0.3% (total=100%) in order of decreasing finish order with Approval. Note the high shares for the two frontrunner parties. The Approval results were 58.0, 41.8, 31.4, 30.3, 10.4, 7.4, 3.9, 2.8% (total=186%) which note gives more to much more relatively to all third parties.
That was in the election for people for their district. There also was a second election for federal parties (Germany has party list) which yielded similar results though with more permuting in the finish order. The paper (4.0.2) also describes a second experiment with 1,431 voters (again exit poll) on 2009 Sept 27. This was 49.7% of the voters in the official election at same places. Now six voting stations in Konstanz. This is to be described in more detail in a different paper, apparently. In this case, Approval Voting actually changed the winner (from the CDU to the Greens). However, this may have been somewhat due to “the fact Konstanz is a university town and not a uniform sample from all of Germany” as opposed to “the voting system change.” The official Germany-wide winner was the CDU and it had a majority of the vote. The Konstanz winner was the Greens with 58.1% approval (while the SPD got 47.4% and the CDU got only 41.5%) the only party to get more than 50% approval.
Note the Greens are a third party, and officially came in third with 20.1%. The average number of approvals per voter was 2.56. Again Approval Voting said there “really” should be 4, not 2, large parties (based on vote share) and the third parties got lots more votes relatively. Konstanz also awarded 20.8% approval to the anti-copyright “Pirate Party” which only got 3.7% of the official plurality vote.