Monthly Archives: July 2014
Extreme events and probabilistic election forecasting: salutary lessons from football
In his article on last week’s forecast, John Rentoul wrote:
“Probability is hard enough to understand anyway, of course. Look at Nate Silver, the guru of American election predictions. He said Brazil had a 65 per cent chance of winning against Germany in the World Cup semi-final. Well, you could say that their 7-1 defeat fell in the other 35 per cent but – after the event – we can be pretty confident that the 65 per cent figure meant little useful.”
There are various issues here in the context of the overall article. Did the 65% figure mean little useful? How should we judge probabilistic forecasts after the event they were trying to predict? Even if John Rentoul’s interpretation here is right, should the poor performance of a football match prediction undermine the credibility of other forecasting exercises of very different kinds of events for the forecaster, or even for all forecasters? Continue reading Extreme events and probabilistic election forecasting: salutary lessons from football
Leadership effects and electoral cycles
In his article on our 11 July forecast, John Rentoul wrote:
“My view, and this cannot be based on opinion polls, is that when the voters come to choose they will shy away from the prospect of Miliband as prime minister, just as they shied away from Neil Kinnock in 1992.”
This view is not so far from being based on opinion polls as suggested. Continue reading Leadership effects and electoral cycles
Speculation on parliamentary arithmetic
This is the second in a series of posts in response to John Rentoul’s excellent article, much of which discussed the politics of our 11 July central seat forecast (Con 296, Lab 295, LD 31; so either Con+LD or Lab+LD would have a majority).
I have mixed feelings about speculation on the parliamentary arithmetic of any particular forecast. Part of the point of the forecasting method is to estimate uncertainty, which is naturally huge this far away from an election. Continue reading Speculation on parliamentary arithmetic
Fluctuations in polls and the timeliness of the forecast
Belated thanks to John Rentoul for his excellent article on last week’s forecast. This is not to say that I necessarily agree or disagree with his views on the desirability of particular election outcomes, just that I think it is a good discussion of lots of issues in politics and forecasting. Continue reading Fluctuations in polls and the timeliness of the forecast
Forecast update: 18 July 2014
Welcome to Elections Etc
What can today’s polls tell us about next year’s election? Quite a lot actually, but only if read carefully. That’s what we try to do here at Elections Etc, combining the polls with analysis of previous elections to predict what will happen on 7 May 2015. Continue reading Welcome to Elections Etc
Forecast update: 11 July 2014
Why is the 2015 general election forecast trending?
A few people have asked me this question about my forecast. The trends are definitely there as you can see from the graphs below. But since they are well within the very broad prediction intervals, there is a danger of reading too much into them. Certainly we are far from having enough information to say the model isn’t working well for this electoral cycle. Continue reading Why is the 2015 general election forecast trending?