Drawing national conclusions from the local battles
We are only 8 days away from the May local elections which at the moment looks as though will be the most significant UK electoral test that we will have during 2018.
One of the problems with looking for national trends from the locals is that very different ranges of seats come up each year and we cannot simply use the party vote or seat totals for comparison. Over a four year cycle in England different types of councils have elections. Thus with the London boroughs, a Labour stronghold, dominating this year an annual assessment on just the aggregate vote would be distorting in the same way in years when the shire counties dominate.
To get round this each year the BBC team, which includes John Curtice, seek to make a projection for the entire country based on the results that they have available. There’s another team as well making a similar calculation – professors Rallings and Thrasher. The latter do it in a different way and I must admit that I have never comprehended the methodological difference between theirs and the BBC numbers.
If this election is similar to previous ones the chances are that the BBC figure will be published first most likely on the night during their election results coverage.
The chart above show the BBC projected national vote share at every set of local elections since 2000. UKIP only came into the equation in 2013 which explains the shortness of the plot.
Last year things were rather distorted by the fact that the general election was called during the local election campaign and on the day before polling day Mrs May made her highly publicised drive to The Palace followed by a speech in Downing Street – something that completely dominated the headlines and the TV coverage.
Unless she’s got something special up her sleeve this time I’m not expecting that such a boost will be possible.