One week on, have the Sunday Herald learned the lessons of their wildly inaccurate reporting on so-called "tactical voting on the list"?

The short answer to that question is "only partly".  As editor Neil Mackay hinted would probably be the case, they've gone big on the subject for a second Sunday in a row, with the lead story once again penned by Peter Swindon.  It's basically another propaganda piece that is pretty unsubtle in attempting to steer readers towards abandoning the SNP on the list, but Swindon has chosen his words somewhat more carefully this time, and in particular has ditched the pretence that John Curtice actually "advised" people to vote Green or RISE. He's also replaced all traces of the totally inappropriate word "predict" with the much more sound "project".  The problem, however, is that he mostly writes as if the two words are basically synonymous, ie. "[Curtice] projected that the SNP will win all but three constituencies". That means the impression conveyed is almost as misleading as last week - but a very hurried caveat of "if an average of recent polls are correct" at least ensures that the new article can technically be claimed not to be inaccurate.

To be fair, there are some contexts in which "project" can be used as if it means exactly the same thing as "predict" - an example would be "CNN projects that Bernie Sanders has won the Michigan primary", which is a call that is never made until it is felt there is near-certainty. But that's not the sort of thing we're talking about in this case. John Curtice's report collated the results of opinion polls which were conducted well before the election, and projected what the election result would be if : a) those polls were bang-on accurate, and b) no changes whatever in public opinion occurred between the dates on which they were conducted and polling day. That's more akin to taking the pre-election polls in Michigan and using them to "project that Hillary Clinton will win comfortably", without bothering with the irritating formality of counting any votes. Indeed, as regular readers of this blog know, that sort of projection was actually made, and it was utterly meaningless - Sanders defied polls giving Clinton a double-digit lead, and won by a whisker.

Do we live in a world where that magnitude of polling fiasco only occurs once in a blue moon? Och, don't be silly. Last year's UK general election was supposed to result in a nailed-on certain hung parliament - but the Tories won an overall majority. Just a few weeks earlier in Israel, everyone thought Benjamin Netanyahu was a dead man walking, but on election night he dismayed the world with a famous victory that bore no resemblance at all to the pre-election polls. And although the Liberals certainly looked set for a return to power in Canada last autumn, the polls offered Justin Trudeau little hope of an overall majority. Come election night, he won a comfortable majority of 30.

Now, perhaps you're on the brink of offering the familiar objection that the polls may have severely misled us in many contests around the world last year, but they did pretty well here in Scotland. OK, so let's take that observation to its logical conclusion. Presumably what you'd be getting at is that the polls can always be relied upon to give an accurate indication of election results in Scotland. That would explain, for example, why we all knew well in advance that the SNP were going to win an overall majority in 2011. Oh, wait. We didn't know that at all, did we? In fact, every single projection in 2011 based upon the pre-election polls put the SNP short of a majority. It was occasionally projected that there might be a slender pro-independence majority consisting of the SNP, Greens and Margo MacDonald, but even that was thought to be reasonably unlikely.

So, no, there is no Scottish exceptionalism that means we don't have to allow for the very significant possibility that the polls and seats projections based on polls are leading us astray. Professor Curtice knows that as well as anyone - he's repeatedly pointed out on his blog that polling on the list was significantly less accurate in 2011 than constituency polling (thus explaining why nobody saw the SNP majority coming), and also that the Greens have historically been substantially overestimated on the list. And that's exactly why he went out of his way in his report to indicate that his projection based on the polls was not a prediction of the election, or functionally indistinguishable from a prediction. He specifically entertained the possibilities that the polls may be understating or overstating the SNP's support, and noted that in either scenario, attempts by SNP supporters to vote "tactically" on the list could easily backfire. And that was absolutely not, as somebody tried to make out in a comment on this blog the other day, some kind of routine, going-through-the-motions "health warning" along the lines of "we all know that the polls will probably be broadly right, but we can't totally exclude the possibility that they won't be". He was deadly serious in what he said - nobody who read the report could be in any doubt that he regarded polling error as a significant risk. That was the whole basis for his verdict that pro-independence voters face a "dilemma" on the list ballot.

Last week, the Sunday Herald totally ignored that side of the Curtice report - they literally pretended it didn't exist. This week, they've belatedly acknowledged it, but are downplaying it for all they're worth. They have a direct quote from Curtice, which in terms of tone seems to offer some comfort to their original misrepresentation of the report, but a close reading confirms that his position hasn't changed one iota. Forgive my cynicism, but I'm inclined to suspect that they conducted quite a long interview with him, and cherry-picked the quote in which he happened to place the weakest emphasis on "risk" and "dilemma". Even so, those words are still very much present.

The other experts quoted in the article are Ipsos-Mori's Mark Diffley and Dr Craig McAngus from Aberdeen University. In contrast to Curtice, I don't have any suspicions that they've been quoted selectively, because what they say seems fairly clear-cut, although obviously it's impossible to know whether the Sunday Herald kept phoning around until they found experts who said exactly what they wanted to hear (perish the thought!). I just think Diffley and McAngus are plain wrong, and some of what they say doesn't actually make any logical sense. Diffley very unwisely uses Swindon-like language and says that Curtice's projection shows that the SNP "will" only get two regional seats. I'm sorry to have to make the obvious point here, but Ipsos-Mori were as wrong as every other pollster last year - a projection based on their final poll in May 2015, and couched in Diffley's choice of words today, would have read : "Ed Miliband will be Britain's new Prime Minister". I'm sure that would make a great alternative history novel, but it wasn't much cop as a prediction.

McAngus, meanwhile, makes the extraordinary statement that "To vote for another party other than the SNP on the list as a pro-independence voter is a rational thing to do. I mean, the way that the numbers stack up, the SNP are not going to win a lot of seats on the list." I can only conclude that he actually hasn't thought this through for more than five seconds, because what all the polls are unanimous on is that the SNP are on course to win some list seats, and that both RISE and Solidarity are light-years away from winning even one list seat. So yes, let's talk about rationality - is McAngus seriously saying that it's more rational to cast a "tactical" vote that seems guaranteed to be wasted than it is to stick with the SNP and at least have a chance of contributing towards the election of a pro-independence MSP on the list? Perhaps we could be charitable and assume that "another party other than the SNP on the list" is code for the Greens, and definitely not for RISE or Solidarity - but a) that's not my impression of what he's saying, and b) even if that is what he means, it's deeply irresponsible of him not to spell it out. It would, in any case, still be a very weak argument, because while the polls offer grounds for optimism that list votes for the Greens will not be wasted in at least some regions, they fall well short of providing conclusive evidence that the Greens are set to win more list seats than the SNP.

I'm also a tad bemused by the article's suggestion that Diffley and McAngus have "backed" Curtice's projection. As the projection simply takes the raw poll numbers and directly converts them into a hypothetical number of seats, "backing" the projection amounts to no more than agreeing that Curtice is adept at using a calculator. In that sense, I'm more than happy to "back" the projection as well, but I'm not sure what that's supposed to tell us in concrete terms.

Finally (and this has nothing to do with the Sunday Herald piece), I want to tackle a line of argument that Tommy Sheridan used in the debate I had with him, and that seems to be taking root in some other quarters as well. Basically he claimed that if the SNP win all nine constituency seats in Glasgow, the d'Hondt formula will ensure that "nine out of every ten SNP list votes will be wasted, and that only one in ten will actually count". This is complete garbage, because it wrongly implies that d'Hondt literally throws away a certain number of votes, which are then not taken into account at any point during the distribution of list seats. In fact, the d'Hondt calculation is made afresh for every individual list seat, and is always based on the actual number of votes cast. The following hypothetical example in which only two parties are involved will hopefully illustrate what I mean.

Actual list vote :

SNP 99,950 votes
Solidarity 10,000 votes

Because the SNP won all nine constituency seats in the region, the d'Hondt formula divides their raw list vote by ten (nine plus one) in the count for the first list seat. Because Solidarity didn't win any constituency seats, their raw vote remains unaltered.

D'Hondt-adjusted count for first list seat :

Solidarity 10,000 votes
SNP 9,995 votes

So Solidarity take the first list seat, and on the face of it the SNP's advantage in terms of votes has been completely wiped out. If you believe Tommy Sheridan's notion about 90% of the SNP's original list votes being literally thrown away, you'd be forgiven for thinking that the two parties are now on an equal footing as far as the distribution of the remaining six list seats are concerned, and perhaps will win three apiece. But that isn't the case at all, because for each remaining seat, the d'Hondt formula refers back to each party's actual number of votes. For the second list seat, Solidarity's original vote is divided by two (one plus one), because they now have one seat under their belt. The SNP's vote remains divided by ten.

D'Hondt-adjusted count for second list seat :

SNP 9,995 votes
Solidarity 5,000 votes

For the third list seat, the SNP's original vote is divided by eleven (ten plus one), because they now have ten seats. Solidarity's vote remains divided by two.

D'Hondt-adjusted count for third list seat :

SNP 9,086 votes
Solidarity 5,000 votes

For the fourth list seat, the SNP's original vote is divided by twelve (eleven plus one), because they now have eleven seats. Solidarity's vote remains divided by two.

D'Hondt-adjusted count for fourth list seat :

SNP 8,329 votes
Solidarity 5,000 votes

For the fifth list seat, the SNP's original vote is divided by thirteen (twelve plus one), because they now have twelve seats. Solidarity's vote remains divided by two.

D'Hondt-adjusted count for fifth list seat :

SNP 7,688 votes
Solidarity 5,000 votes

For the sixth list seat, the SNP's original vote is divided by fourteen (thirteen plus one), because they now have thirteen seats. Solidarity's vote remains divided by two.

D'Hondt-adjusted count for sixth list seat :

SNP 7,139 votes
Solidarity 5,000 votes

For the seventh and final list seat, the SNP's original vote is divided by fifteen (fourteen plus one), because they now have fourteen seats. Solidarity's vote remains divided by two.

D'Hondt-adjusted count for seventh list seat :

SNP 6,663 votes
Solidarity 5,000 votes

As you can see, and entirely contrary to Sheridan's claim, the fact that the SNP has ten times as many list votes as Solidarity matters enormously. It ensures that after the initial big hit on the first count, the SNP's vote only comes down very, very gradually in subsequent counts. By contrast, Solidarity never recover from having their vote cut in half on the second count, and they lose ALL SIX remaining list seats to the SNP. Final number of list seats in this hypothetical scenario : SNP 6, Solidarity 1.  So much for nine-tenths of those SNP list votes "not counting", eh?