some random exit polls/election day polls for other ballots Feb 20, 2020 22:16:25 GMT via mobile nodealbrexiteer likes this
Post by Georg Ebner on Feb 20, 2020 22:16:25 GMT
I’m afraid the projections throughout the day in the 2001 exit poll were never published so far as I know.
You are quite right that national uniform swing is a fairly poor predictor of the number of seats won these days, and for that reason we have never used it in our exit polls. However, uniform swing across smaller groups of similar constituencies is a much better predictor, and in one form or another is the basis of all seat-projection exit polls in electoral systems that do not use proportional representation (although strictly speaking what we use is not swing but change in the parties’ shares of the votes, since there may be more than two parties whose vote shares are relevant). In the case of our 2001 poll, our polling was entirely restricted to marginal constituencies – much of the reason why national uniform swing fails as a predictor is that the swing can be different in safe seats and marginal seats, and of course it is only the swing in marginal seats that matters since the safe seats are won by the same party regardless. Within the marginal seats, we distinguished between Conservative/Labour marginal and Conservative/LibDem marginals, and we measured the swing in each set separately – by using the poll to estimate the swing in Con-Lab marginals and applying that swing uniformly across all those constituencies we got a pretty accurate projection of the number of those seats that would change hands.
In fact we had the capacity to make the model more complex – for example, if the data had suggested that a particular region was swinging differently from the rest of the country, we could have applied a different swing in those constituencies which might have changed the seat projection. (Professor Colin Rallings, who was ITN’s academic consultant, was in overall charge of making the final projection from our polling data and had to make the decision whether to apply any differential swings or not.)
As you may know, for the last two general elections we have combined with Gfk-NOP to conduct a single exit poll which is used by both BBC and ITV (and Sky in 2010), and the academic team that makes the projections from the data is now led by Professor John Curtice. They use more complicated statistical methods to help them analyse the data as it comes in, and they use a more sophisticated “probabilistic” method rather than simple uniform swing, which in effect allows for small random variations in swing within a broadly uniform pattern. But in fact the essence of the method is still the same – different uniform swings applied to several different groups of marginal seats, and the final decision made during election day which groups to treat separately and which to combine. In 2010, for example, they used different figures for the swing in England from the swing they used in Scotland and Wales.
I hope that helps.
Grouping the early incoming precincts into clusters (cities, towns, young/old aso.) is also conducted during ElectionEvenings in PR-countries in order to calculate the FinalResult.