Heresthetics and the alcohol purchase age
I lost about $300 on iPredict a little over a month ago. I had really strong expectations that the Government’s bill proposing a split alcohol purchase age was going to pass. Standard rules of order seemed to ensure that the government’s bill would pass. The amendment to keep it 18 would fail as all those preferring Split or 20 would vote it down; the same would hold in reverse for the amendment to increase the age to 20 across the board.
In the wake of the parliamentary vote on alcohol purchase age there are some people (the ones I have seen are people who favoured 20) who are suggesting that the voting procedure used led to a perverse outcome.I disagree completely. This is not a post about the merits or otherwise of the various options, but an argument that while the voting procedure was highly unusual, it produced a more democratic outcome than otherwise would have occurred, and should be considered more often. [emphasis added]
So recall that in this case the option that was in the Bill was the split age option, but that there were proposed amendments both to retain a uniform age of 18, or to raise it to a uniform 20. The ordinary House process would have seen first a vote on 18. If that had passed then the 20 proposal would have been ruled out of order. If it had failed we would have voted on the 20 option. If that had failed then the split option would have remained in the Bill.
Under the traditional voting method, what would have happened is this: the proposal for 18 would be put and fail. We would then have moved on to the 20 proposal, and this also would fail. This would leave the split age in the Bill – the option that was actually the least favoured by MPs.
Instead first preferences were canvassed and the split age option, as the least favoured excluded. Then effectively those who had favoured the split age added their support to their second preference. Hence 68 votes for 18, 53 for 20.The voting method used ensured that the result could command a majority in the House whereas the traditional method would not have done (except by excluding this whole part of the Bill I guess).
- There was a Condorcet winner: Split would have won against both 18 and 20.*
- The system we used, which ruled out the Condorcet winner on the first round, was more democratic.
- Flip from the normal rules of order and convince everybody that you’re doing it for fairness reasons rather than to change the outcome.
- Do it late enough in the game that all the “Increase to 20” group don’t have time to think through the game theory. If you do it early, somebody will point out to the ones too dim to figure it out on their own that they cut their own throats by supporting 20 over split at the first round, if their true preference ordering has 18 last. 20 then gets dropped in the first round and Split wins in the second.
- Do it despite the government seeming to prefer the split age option, which lets them to be seen to be doing something on alcohol, where there’s been a lot of public pressure.