This is interesting:
One of the other issues which Mr Mundell has been exploring is whether the Coalition Government might be able to amend the current laws to force the Scottish Government to ask a clear Yes/No question on independence.
Mr Salmond has made it clear he favours a three-option referendum with the Scottish people being asked to back full independence, the status quo or "independence lite" – a settlement which many unionists believe would leave Scotland independent in all but name.
There have also been suggestions from the Nationalists that Scots would be able to choose more than one option in the referendum – prompting critics to warn that the SNP could secure independence even if this was only the second-best supported option.
Peter Kellner of YouGov has a good run down of all the possible ways of asking this question apart from two-questions. Although the SNP seems to be backing down from a two-question route they're leaving a space open for it to return, and ERS Scotlandis advocating a different form of the two-question format, making it worthwhile having a look at exactly what the problems are with it.
One possible set of questions (Set 1) would be:
1: Do you prefer independence to the status quo?
2: Do you prefer devo-max to the status quo?
This question choice could lead to the situation where both independence and devo-max receive majorities (or even, for the purposes of argument, super-majorities) but devo-max receives a larger majority than independence - what then does the referendum say should be done about Scottish independence?
One answer would be that the Scottish government would at that point be well within its rights to declare independence, a majority has declared its support. The other way to argue it is that when there are two possible consensuses on offer, a democracy should seek to create the largest possible consensus - which in this case is devo-max and it'd be wrong to leave the union when a strong majority is in support of it. As a convincing case could be made either way Set 1 creates the possibility of an ambiguous result, which is bad.
There is something seemingly nonsensical about the idea a majority can be in favour of both the union and independence which gives us a clue as to where Set 1 went wrong. The problem is that although it seems like we do, we don't actually have information on if people would prefer independence to devo-max or vica versa. If 'status quo' is A, 'independence' is B and 'devo-max' is C, we have information that B and C are superior to A (to differing degrees), but we can't from this deduce people's ordering of B and C. If you replaced all voters who preferred C to B to A with voters who preferred B to C to A the questions in Set 1 would still return exactly the same result. Given in the situation above we're trying to work out which winning claim is superior, that all the people who actually have opinions on this can change their mind without affecting the result is a problem.
If the SNP want to use this question they're really shooting themselves in the foot. It's highly likely that if independence can win a majority then devo-max will be able to win a higher majority and so make any resulting move towards independence appear illegitimate - which it may or not be because we have no way of knowing which of B or C voters prefer. One alternative set of questions (Set 2) would be:
1: Would you like a change to the status quo?
2: Would you prefer independence or devo-max?
This set was pretty much the format used for the 1997 Scottish referendum and one of the possibilities that was occasionally floated for an electoral system referendum. Willie Sulivan at ERS Scotland argues that:
“If there is only to be one question then the structure is straightforward; a simple Yes or No for Independence.
“If the consultation responses indicate that the Scottish people want the opportunity to vote on all three options, then the best way to do this would be to ask two questions on the same ballot paper: The first asking yes or no to any change and the second to determine what level of change. This approach was recently road-tested in New Zealand.
“This is by far the simplest and fairest way to ensure that everyone gets a real say but we are concerned that instead of ensuring that it’s the Scottish people who have a chance to determine Scotland’s future, the debate among politicians is becoming polarised and disingenuous.”
But I think especially in the context of this referendum, this question set can end up treating a particular group of voters unfairly - while at first glance this seems to solve the problem above by giving a clear choice between B and C, but it doesn't allow people to place A(status quo) as a middle preference. Say we get a majority in favour of change in question 1 and a majority in favour of independence in question 2, we have information that a majority prefer B or C to A, and that a majority prefer B to C. The problem is that the ballot design assumes A is either a voter's first or last preference. If question 1 could be swung by a single vote but question 2 already had a majority for independence, a voter who wanted devo-max, but doesn't want independence (and so has the status quo as their second choice) will vote yes on question 1 - giving independence victory despite the fact that that was not their intention.
From these we can see that it's very hard to get people to choose between more than two options using two yes/no questions and that there are grounds for restrictions on the kind of questions and not just the wording that should be asked in referendum (although this should probably be done by the Electoral Commission rather than a political stitch-up in Westminster). This leaves either a single yes/no question on a single issue, adding another yes/no question to make it a Condorcet vote as Kellner recommends, or preferential voting among multiple options using AV - of which the last for me seems the simplest method of better way of determining what people actually want. Obviously this was a non-starter in an AV referendum as conceding that voters are capable of dealing with multiple preferences would have been giving the game away, but many Scottish voters already use preferential voting with STV in local elections so there's no real reason why it couldn't be used - 'simpler' formats really aren't simpler.
(This post was updated on 26/01/2012 to include references to various groups as statements have been made and evolved).