OK it is election time again here in the UK and the Conservatives have the upper according to many polls and surveys monitoring the voting intention of UK voters. Though there are many surveys and polls the data available is quite noisy and also inconveniently irregularly spaced. This makes it difficult to detect trends and evaluate possible scenarios. In an attempt to bring some clarity I use UK polls survey results since the May 2010 sourced from the UK Polling Report website. They provide the results of 2172 polls made since may 2010. I First aggregate the data by calculating the weekly means of all the surveys, generating a sample of 344 weekly estimates. As shown in the below charts this greatly reduces the noise in the data .
As of the week ending 2017-04-24 the average percentage of intention to vote was standing at 49.11 % for the Conservatives, 27.44 % for Labour, 11.81 % for the LDEM, 8.53 % for UKIP and 3.11 % for the Green party.
The following charts show for each party the historical distribution of the percentage of vote intention (since 05/2010 for Conservatives, Labour and LDEM; 04/2012 for UKIP and 07/2012 for the Green party), the current level at which it stands (vertical green line) and its mean over the whole sample (blue line).
Finally the below provides an arima forecast of the percentage of vote intention by party and the 95% confidence intervals based on the previous 52 weeks of data. Each forecast is based on the best fitted ARIMA over the history used.