Shy Tory factor

"Shy Tory factor" is a name given by British opinion polling companies to a phenomenon first observed by psephologists in the early 1990s.

[1][3][4] The final opinion polling for the 1992 United Kingdom general election gave the Conservatives between 38% and 39% of the vote, about 1% behind the Labour Party, suggesting that the election would produce a hung parliament or a narrow Labour majority and end 13 years of Tory rule.

Following the 1992 election, most opinion pollsters altered their methodology to try to correct for this observed behaviour of the electorate.

[5] In the 1997 United Kingdom general election, the result produced a smaller gap between the parties that polls had showed but a big majority for the Labour Party because the swing was not uniform; the polling companies that had adjusted for the "Shy Tory effect" got closer to the voting proportions than those that did not.

[10][11] This enquiry found that, contrary to the popular reporting, there was no "Shy Tory factor" in the election, and the polling had been incorrect for other reasons, most importantly unrepresentative samples.