Punters versus pollsters

DURING the run-up to Scotland's referendum on independence, the polls wobbled but gamblers, as revealed through the betting websites, were steadfastly confident that the No side would prevail. They were right. The margin was wider than some polls had suggested: 55% opposed to independence and 45% in favour.

So what do the gamblers say about tomorrow's general election? Like everyone else, they seem flummoxed; 11 out of 20 bookmakers (figures from Oddschecker) have identical odds for David Cameron or Ed Miliband being next prime minister. Of the rest, five have Mr Miliband slightly ahead and four tilt towards Mr Cameron.

This uncertainty reflects the opinion polls. On average, the past 10 polls have put the Conservatives narrowly in the lead, with 33.2% to Labour’s 32.9%. Then come UKIP with 13.6%, the LibDems with 9.2% and the Greens on 5%. Translate that into seats on the basis of five different online electoral models (May 2015, Election Forecast, Elections Etc, Poll Observatory and the Guardian) and the Tories maintain their advantage. They would have 278 seats, Labour 267, the Scottish Nationalists would have 54, LibDems 26, UKIP 2 and the others (including Greens) 23.

However, that would still leave David Cameron short of a working majority (effectively 323 seats). Adding in the LibDems and perhaps 8-10 Ulster Unionists would only get Mr Cameron to 312-314. Even if he swallowed a deal with Nigel Farage’s UKIP, he would not get over the line.

If the models are right, the anti-Tory bloc of Labour and the nationalists is on course for at least 327 seats, more than enough to vote down a Conservative government. Mr Miliband should be the narrow favourite to be PM. On this basis, the gamblers seem to be slightly overestimating the Tories’ chances.

So what are the gamblers counting on? A late swing to the Conservatives, or “shy Tory” voters who did not reveal their preferences to pollsters? Or simple mismeasurement? Phone polls show the Conservatives ahead by around 3 points; online polls show the two parties tied. Perhaps the answer is an unconscious preference among gamblers (many of whom may work in the finance sector) for the Tories. They may get a nasty shock on Friday.