Who should Green voters back with their constituency vote in next year’s Holyrood election? I am not aware of Green candidates standing in any of the constituencies this time, although that’s a decision for individual branches to make. Assuming I’m right about those branch decisions, the dedicated Green voter will have to look elsewhere if they cast a constituency vote.

Is there a clear policy answer?

Surely this is the best place to start? Where a Green voter faces a choice of Labour, SNP, Lib Dem or Tory in their constituency, which of those four has been the best on the that motivate our voters? To oversimplify, I’ll look at social justice, civil liberties, the economy and of course the environment.

The Tories and the Lib Dems obviously score more poorly on social justice, the economy and the environment given the Westminster coalition, but if civil liberties are your priority, they might make sense (with a couple of serious reservations). In fact, if civil liberties come top for you, you’d be voting for anyone but Labour, although most of their failures on this front have been at a Westminster level, not Holyrood, but should we disassociate the two when Labour campaigns in Westminster elections on knife crime etc?

On the economy the choice is harder. All four other parties backed the bankers and fell for the idea that boom and bust was over, during an unstable boom. None of them question the economic system so comprehensively excoriated by Neal Ascherson in the Sunday Herald a while back (perhaps the best thing I’ve read all year). None of the three parties who held Westminster office during 2010 have shown any inclination to make the tax system more progressive, given the impact of the increase in allowances. Similarly, neither the SNP’s Local Income Tax proposals nor their Council Tax freeze can plausibly be identifed as progressive. It also seems unlikely that any of the other parties will propose a revenue-raising alternative to passing on the cuts, an area where another progressive proposal from elsewhere might well have tempted Green tactical voters to commit a first vote.

On the environment, none of them have a great case to make, (though I have to bow to James’ more detailed knowledge on this score), but there are points of difference. The SNP score for being anti-nuclear, but lose for being pro-coal. Labour score for being against some coal at least, but lose for being pro-nuclear. On climate change targets, the Westminster Coalition parties and the SNP lose points for voting for very weak targets last year, where Labour get a grudging half point for abstaining. Not one of them gets a single point on transport: all four other parties back every one of the unpopular motorway schemes currently under consideration, and all four back airport expansion.

In short, there’s no clear guide on policy for the Green voter looking at the constituencies, and it would depend on what each voter’s policy priorities were.

And looking at the tactical votes?

Now we’re talking!

One of the widely touted advantages of PR, of course, is an end to tactical voting. In general that’s true – with STV, you should just vote your first preference first, then rationally go down to the penultimate candidate or party. With a pure party list system it would only make sense not to put your real first preference party first if you thought they couldn’t win, and if there was a decent enough compromise party worth backing instead.

However, Scotland’s system, as the fellow anoraks who read this blog know, isn’t pure PR – it’s AMS with 73 seats elected by the tired old First Past The Post system and then “topped up” by the second vote in the region.

Of course, before you start counting the list votes for each region, you divide each party’s vote by the number of constituencies they won, plus one. That neatly avoids having to divide by zero, of course, which is infinity, or zero, depending on your mathematical know-how.

This means that, in Glasgow for instance, Labour list votes have always been irrelevant. In 1999 and 2003 they won every constituency, and even in 2007 only a Nicola-shaped pocket of neon yellow punctuates the sea of pale red.

This makes it a hard region for Greens, Conservatives and Lib Dems to win seats in off the list, but Nicola’s win made it that little bit easier for the rest of us. If she’d lost in Govan, Patrick would have lost on the list, simple as that. So tactically, Green list voters (and indeed Lib Dem or Tory list voters) want to see her win again, and if Labour were somehow to lose another constituency that would help Glasgow’s three smaller parties too: that would be where the pure tactical interest lies.

To take a slightly different example, a hypothetical Green voter who lives in Edinburgh Pentlands would have had some tough choices over the year. From 1999 onwards it was clearly the Tories’ number one target in the Lothians, and one thing has been constant about their results in the capital’s region: they get two MSPs elected. In 1999 they lost out in Pentlands and took the compensatory list seat. In 2003 and 2007 they won Pentlands and freed up a slot in the lists.

If David McLetchie hadn’t won Pentlands in 2003, Colin Fox wouldn’t have claimed that last list slot behind Mark Ballard. Curiously, therefore, the purely tactical constituency vote in Pentlands for a Green, or even for a Socialist, would be for Tory MSP David McLetchie. There’s virtually no risk Parliament would have any more Tories in it, so why not?

Who might tactically vote Green?

The flip side of this question is to ask when it might suit supporters of other parties to lend a second vote to the Greens, and the obvious examples are regions where a party’s list votes simply don’t get MSPs elected. And there are loads of them.

For this purpose we can ignore the Tories, not just because Green is the second vote of typically about one Tory in fifty, but also because they have won list seats in every region at every election. Having opposed PR. Good work.

The SNP are also in a different category – they have won seats in every region at every election too, but we do attract a fair number of SNP second preferences. In fact, the case has previously been made that, given those pesky d’Hondt divisors, voters who prefer the Green position on the constitution get more bang for the buck voting Green on the lists.

Those entire regions where list votes simply don’t elect anyone from larger parties are most interesting, though. The table shows where list votes were simply discarded, election by election.

There has therefore been larger-party wasted list votes in every region and at every election except the North-east last time. In some cases it may be hard to predict where that will apply, but in others it’s a virtual certainty.

If you were a Labour voter in Central, Glasgow or West, wouldn’t you rather express a preference that might elect someone on the list? For sure, there’s a substantial statement made by all those discarded Labour list votes – “we are really loyal to Labour” – and you never know for sure how the constituency vote will go, but voting for another party could make a real difference. Are those voters really neutral about whether Glasgow has more SNP, Lib Dem, Tory or Green MSPs? Or do we need to explain the voting system better? The same applies to Lib Dems in the Highlands and Islands, whose list votes have never helped anyone get elected.

There are Labour activists who work on this basis, who split their vote to get Greens in on the lists instead of SNP or Tory MSPs. There has been (confidential) suggestions from an SNP activist that they might think about it in a region or two. But will it spread? And will the public follow suit?

There are lies, damn lies… and then there are opinion polls.

I want to make clear, I have no real agenda here.  Weighted, unweighted, likely to vote… I’m really not sure how much they tell us.  As one of our commenters noted, on the doorsteps the response most heard to the question “with which party do you most closely identify” is none.

But by all means, knock yourselves out with speculation – as indeed, you have been doing – whenever a new one comes our way.  I want to add to it based on nothing more than an idea that came to mind.

I’ve been saying for a few months now that I think the likely outcome is a narrow Labour “victory” – that’s to say, more seats than any other party in Parliament, but not enough for a majority (of course) and with the maths making coalition with anyone unlikely if not impossible, running a minority government.

But here’s a spanner for you.  What if that came to pass, and Labour did become the largest party… but Iain Gray failed to be re-elected in East Lothian?

Let me back track a little.

• Iain Gray was Minister for Enterprise, Transport and Lifelong Learning (and quite how those three briefs fitted together nicely is anyone’s guess) at the dissolution of the first Scottish Parliamentary session in 2003 – a fairly high-profile role.
• He then lost out in his bid to be re-elected in Edinburgh Pentlands to then-Conservative leader David McLetchie, with the latter turning a 2,885 Labour majority into a 2,111 majority for the Tories.
• Given Labour’s rules regarding standing in either the constituency or on the list, but not both, he was thus denied the “safety-net” of list ranking.
• He then spent 4 years out of Holyrood before returning as constituency MSP for East Lothian after incumbent Labour MSP John Home Robertson decided to step down.
• He’ll be defending a majority of 2,448 over the SNP (which, if you’ve been paying attention, you will have noticed is SMALLER than the majority he held when he lost Edinburgh Pentlands in 2003).

Having said all that – David McLetchie did have a much higher profile than Gray’s nearest challenger in East Lothian, the SNP’s David Berry.  There is a certain other candidate in the constituency who has a high profile – possibly a higher profile than Gray himself – and that is the Conservatives’ Finance Spokesman, Derek Brownlee.  If the Conservatives had been the nearest challenger to Labour previously or were not 6,000 odd votes behind Labour (or, indeed, if the constituency wasn’t essentially allergic to blue!), I’d probably be giving the idea that Iain Gray might not be returned more consideration.

Nevertheless, East Lothian, for all its Labour-leaning tendencies, is not what you would term a “safe” seat, so there is a chance, albeit slim, that Iain Gray might lose the seat itself.  No, I know – I’m not convinced either – but let’s roll with it for a minute.

Now, assume I’m right about the election – and Labour do end up the largest party, but without their leader elected.  What then?

Well, the Scotland Act says we have 28 days to find a First Minister or we have to have a new election.  Labour’s leadership contests take about 3 months, so that’s out – but they managed to have a contest within the 4 weeks in the wake of Donald Dewar’s death.  So, if they wanted to govern, they’d have to act quickly.  But in the meantime, they’d (presumably) be led by Deputy Leader Johann Lamont unless she decided to stand in the leadership contest itself (or, herself wasn’t returned to Holyrood).

I guess perhaps I’m getting ahead of myself a little in considering potential leadership (and, potentially, if my maths proves accurate, First Ministerial) candidates, but presumably Andy Kerr would be favourite, with Jackie Baillie, Bill Butler and John Park (and maybe Johann Lamont herself?) potential candidates?  I have no idea.  I don’t really want to think about FM Jackie Baillie.

Anyway – this is a scenario that is unlikely to trouble us much.  Perhaps possible, but no more than that.  But it would certainly be interesting to see the dynamics of an internal election where, once again for Labour, the winner would become Scotland’s First Minister.