Is the trend with MORI really quite positive for him?
After taking my profits in the mayoral betting last week the odds following last night’s debate have shifted enough for me to start risking some cash again. A price of 4/6, which has been available on Betfair, looks a fair value bet especially after reviewing the detail of the latest polling particularly from MORI.
The firm has had three published surveys on the race and produces, effectively, four sets of figures with each poll. Quite often figures that are highlighted are the ones that are most in line with the publications view of the race and this can sometimes be misleading. Thus on Sunday the Observer barely mentioned that Ken was 6% behind on first preferences.
With each MORI poll you have a series of figures based on all those interviewed naming a candidate and a set of figures on those who say they are certain to vote. These are then broken down into first preferences and what the position looks like after second preferences have been taken into account.
So taking the all naming a candidate first preference series this was KEN 44%: BORIS 33%: BRIAN 16% in February. The first poll of April had this at KEN 45%: BORIS 38%: BRIAN 11% while by the time of the weekend’s Observer findings this had shifted to KEN 42%: BORIS 42%: BRIAN 12%.
The pollster’s headline figures are based on those “certain to vote” and has moved like this.
The final series of figures are based on what happens when you allocate the second preferences of those certain to vote. You have to be careful here about rounding as I pointed out last week after the Unison funded survey. The margin can only be an even number and this had Ken up 2% in the first two surveys and down 2% in the latest poll for the Observer.
The actual split based on all naming Ken and Boris amongst the certain to vote was KEN 48.54% BORIS 51.45%. So on the rounding the headline figures was right but this disguises the fact that Ken’s deficit was almost 3%. Now that might not seem a lot but we are in a very tight election where the winner takes all.
Another element is that in the latest poll MORI asked whether respondents might change their mind. Here the split of those who had definitely decided was KEN 63%: BORIS 71%: BRIAN 44% – so Boris’s vote appears to be firmer than that for the other two.
The final factor, of course, is turnout and in the latest poll MORI found that the number of “certains to vote” was up from 48% in the earlier two surveys to 54% – an indication of how interest in this contest is increasing.
I don’t think that the final proportion will reach that level but it looks fairly certain that it will be up substantially on the 37% of four years ago. I do think that Ken benefits from a higher turnout and that, at the end of the day, might be the decider.
Today on the site: I am off to London to see the Howard Brenton play on Harold Macmillan at the NT and won’t be back until late. Scheduled to be published at about 4.45 pm is an article by Rod Crosby examining the possible impact of different regional swings at the next general election.