It's Still Referendum Time.

Although the polls in Britain's Alternative Vote (AV) referendum and, in some places, local elections don't close until 10pm (22:00) I went and voted at lunch time. While I was doing that I realised another problem with AV.

In Britain and elsewhere central to the principle of democracy is the idea of the secret ballot where, unless they choose to tell you, no-one knows who voted for which candidate. This allows people to vote for who they truly want to win free from pressure from friends, family members or employers. It also prevents people who voted for a losing candidate being woken up in the middle of the night by a nasty knock on the door when the winning candidate takes power. When you consider the sort of harassment that political protesters often have to put up with it is sadly not too difficult to imagine things like that happening in Britain.

The way we maintain the secrecy of the ballot actually has a lot to do with the physical mechanics of how each vote is cast. After applying in writing each voter is posted a polling card containing their name, address and a serial number. At the polling station this polling card is checked against the electoral register and if it matches the voter is given a ballot paper. This ballot paper also contains a unique serial number to prevent it being copied and re-used. This serial number is different from the number on the polling card and is assigned on a first come first served basis so, in theory, there is no way of knowing which voter used which ballot paper. Under First Past The Post (FPTP) the voter then takes the ballot paper into a curtained off voting booth, puts a simple X next to the candidate they want to vote for, folds the ballot paper and slips it into a sealed ballot box. Although Britain's political constituencies are all different sizes the mathematical ideal is 75,000 voters per constituency casting their votes in 7 ballot boxes in 7 polling stations. So assuming a 50% voter turn out there will be roughly 5000 ballot papers used in each ballot box. So if you were to examine the ballot papers you've got roughly a 1 in 5000 chance of guessing which ballot paper belongs to which voter.

The AV system dramatically shortens those odds by requiring the voter to write down a numbered preference next to the candidates. This brings in a persons handwriting as an identifying factor because while most people write a simple X in much the same way there are often huge differences in the way that people write numerals (1's, 2's, 3's etc). Plus when you rank the candidates you are leaving a fairly unique identifying pattern on your ballot paper. Assuming that there are 10 candidates and every voter ranks each candidate there are 1000 possible variations of what the pattern can be giving you a 1 in 5 chance of guessing which ballot paper was used by which voter. That's the sort of ratio you can use to start checking ballot papers against known samples of voter's handwriting and suddenly it's not a secret ballot anymore.