Betting and the 1997 British General Election

How good are political gamblers and bookmakers at predicting election results? In 1997, despite indications from polls, betting markets badly underestimated Labour's Parliamentary majority. But the same applies to a panel of expert 'pundits' and the public generally. The predictions of punters move reasonably in line with pundits and public. And the betting industry scores better when examining percentage vote share. It was close to getting this right, narrowly beating the pundits and all the pollsters. Punters were right to believe polls overstated Labour's percentage lead, but wrong to miss the fact that differential swing would boost its Commons majority.