Why do different amounts of people vote Conservative as the number that tell polls they are going to?

Those who covered the 1992 General Election still talk about it with awe. With days to go, Labour had a 6% lead in the polls. The day after the election, Conservative Prime Minister John Major had been elected with what is still the highest ever popular vote for any political party in Britain…over 14 million people.

It caused ructions in the Labour Party, who had had enough of losing to the point that they decided to fight the Tories by electing one as their own leader (yes, I know, a bit cheeky but nothing wrong with a bit of political banter).

Pollsters, though, had a bigger problem. They were paid to make predictions, and if they couldn’t do that then what was the point of their existence? So, they had to try to explain how they had got it so wrong, and Robert Hayward came up with the most plausible explanation – that of the “shy Tory” voter.

For various reasons, people don’t like to admit that they are intending to vote Conservative at the next election, particularly to a stranger on the phone. This, I imagine, is related to the vitriol reserved by those on the left for those who have right wing leanings. You won’t tell a stranger that you intend to vote Conservative as you don’t know how they might react. If you don’t know what I mean by this, compare sitting down at a table of a Die-hard Labour supporters and announce you are a Conservative-voter with sitting down at a table of Conservative supporters and announcing you intend to vote Labour. The latter will most probably result in amused indulgence. The former won’t.

It’s the same phenomenon that was occurring in Scottish Referendum polls last year, with people not wanting to admit they were planning to vote “No” to a stranger due to the increasingly hostile reaction those supporting the “No” campaign were receiving. The shy “No” voter in this case actually caused far more problems than embarrassed pollsters..our politicians ran up to Scotland and gave away most of the UK’s sovereign powers to them in panic.

Hayward pointed out this week that the “Shy Tory” syndrome was striking again, with his analysis of recent by-election results showing there is still a difference between the number of people saying their intention is to vote Conservative and the number of people who actually do. For instance, in Rochester & Strood nobody predicted the Tories would come as close as they did to winning, with the difference being about 5% between the vote share predicted and the share they got.

That’s not to say that these particular Tories were shy for the same reason though. Hayward points out that with UKIP being the main competition it was unlikely people were uncomfortable on this occasion making their support for the Tories public. Instead, what seems to have happened is that, in the quiet, private sanctuary of the ballot box, people make a different decision.

This decision tends to be the risk-averse one. Those thinking of voting for a smaller party may just not quite go through with it and go back to the larger party they were thinking of voting for. Then those thinking of changing their vote from Conservative to Labour may just find themselves not prepared at the moment they vote to make that leap (perhaps they imagine Ed Miliband coming down the helicopter steps at the White House during a crisis?).

Robert Hayward has looked at this data and predicted that whatever the polls say in the weeks before the election, we should expect the Conservatives’ vote share to be higher. He suggests that if Conservatives and Labour are level-pegging, the Conservatives are likely to win on vote share by between 3% to 6%.

That, of course, doesn’t mean they are as likely to ‘win’ the election. Such is the unbalanced nature of our election system that Labour could get up to 5% less on vote share than the Conservatives and still win more seats. It’s worth remembering that polls you see are not based on individual constituencies but on a uniform swing in voting.

That doesn’t mean, however, that ‘Shy Tories’ won’t make a difference. Watch out for them.