You Gov 2016 – a review part 1

This is a review of the You Gov’s 2016 political polling, a year perhaps the most politically tumultuous for decades.

You Gov surveys are published frequently through the year, and include sub-groups by region and voting identification by how respondents voted in 2015.

The chosen method of assessment was EWMA (exponentially weighted moving average). This technique can detect small changes in consecutive data points. Upper and lower limits are generated based on the data, and breaching either limit is considered a significant event. Given there is a risk of some sample points being outliers, this method which calculates each EWMA point based on a range of data points is resistant to this.

This analysis was performed using R and the qcc package.

Here is a summary of the data.

Here is a table of the data points and the date of the related poll:

Headline Voter Intention (excluding Don’t Know and Will Not Vote)

The Conservatives

Up to the EU Referendum, Conservative VI fell, but from after the referendum (data point 5) they gone from strength to strength. The last poll of the year breached the upper limit, demonstrating statistical significance.

Labour

Quite the reverse to the Conservatives, a pre referendum improvement has turned into a fall in support, with the last two polls of the year breaching the lower limit.

UKIP

Like Labour, UKIP’s post-referendum performance been poor, breaching the lower limit three times in the last five polls.

Lib Dem

The Lib Dems have shown an upward trend since data point 14 (19.09.16). While the upper limit hasn’t been breached, it is very likely one more good poll will achieve this.

The Greens, SNP or PC have no been included in this section due to their share of Voter Intention nationally being too small.

Summary

• The Conservatives have finished 2016 in a much stronger position. Their trend has been positive since the EU Referendum and replacing David Cameron.
• The Lib Dems have shown signs of improvement in the last quarter of the year.
• Labour had a slump after the EU Referendum, stabilised for a time, and have slumped even further since the re-election of Jeremy Corbyn as leader.
• UKIP have declined solidly since the EU referendum.

Current Voter Intention by 2015 GE Party Support

This is interesting at it follows how people would vote for now, grouped by who they voted for in the 2015 General Election. This can show if a party’s headline VI has changed, where their voters gone to.

2015 Conservatives supporting Conservative

2015 Conservatives did drift away from the Conservatives from the start of the year up to the EU Referendum. However, they have since come back since then and stabilised in the last quarter of 2016.

2015 Conservatives supporting Labour

2015 Conservatives supporting Labour has not moved significantly for the whole year, with no upper or lower limits breached, or firm pattern or direction.

2015 Conservatives supporting UKIP

2015 Conservatives did increasing move to UKIP at the start of the year, but post referendum have reduced in number. The current level is about a third of the peak, and half the level of the start of the year.

2015 Conservatives supporting Lib Dem

All data points lay within the control limits, and there are strong patterns of change present.

2015 Conservatives Don’t Know and Will Not Vote

There was an increase early in the year in 2015 Conservatives to Don’t Know, but this group reduced and stablised.

There have been no changes or reliable patterns. As it were.

2015 Labour supporting Conservative

From the year start to the EU Referendum, 2015 Labour to Conservative numbers fell, but then increased, now stabilising for some time.

2015 Labour supporting Labour

2015 Labour voters increased their support for Labour up to the referendum, but fell afterward before stabilising. In September support started to fall again, and the last five polls have fallen through the lower floor.

2015 Labour supporting UKIP

In 2016, 2015 Labour voters switching to UKIP really hasn’t changed. Despite claims of Labour voters switching to UKIP in increasing number, You Gov polls provide no evidence of this.

2015 Labour supporting Lib Dem

Up to the referendum the number of 2015 Labour supporting the Lib Dems fell. However, after a period of stabilisation,  following the re-election of Jeremy Corbyn 2015 Labour voters are switching their VI to the Lib Dems sharply. Three of the last four data points breach the upper ceiling.

2015 Labour Don’t Know and Will Not Vote

2015 Labour Don’t knows have been stable, but since the re-election of Jeremy Corbyn the number of Don’t Knows have increased, very close to breaking through the upper control limit.

2015 Labour Will Not Vote are stable.

2015 UKIP supporting Conservative

 

2015 UKIP voters supporting the Conservatives fell significantly before the referendum, but have since increase very sharply. The last six polls breach the upper limit, and three times more are supporting the Conservatives than a year ago.

2015 UKIP supporting Labour

This category has remained very small and very stable. Nothing happening here.

2015 UKIP supporting UKIP

Since a brief pre referendum boost, 2015 UKIP voters supporting UKIP has fallen sharply. Three of the last five polls and breached the lower limit.

2015 UKIP supporting Lib Dem

This has been stable, except since the autumn, where there is a improvement for 2015 UKIP voters supporting the Lib Dems. However, bear in mind a few percent of UKIP’s 2015 votes is a really very, very small number of voters

2015 UKIP Don’t Know and Will Not Vote

No clear patterns evident, no change.

2015 Lib Dems supporting Conservative

There are no data points outside the control limits. While there a small trend in the middle of the data upwards, it is not significant enough to break a control limit.

2015 Lib Dems supporting Labour

Again, no significant trend is present, but from about September the number of 2015 Lib Dems supporting Labour looks to have lessened a little.

2015 Lib Dems supporting UKIP

All data points are within the control limits, with no trends present. Nothing has changed.

2015 Lib Dems supporting Lib Dems

All data points are within the control limits, with no trends present. Nothing has changed.

2015 Lib Dems Don’t Know and Wll Not Vote

No significant changes with either.

Summary

Headline VI

• Conservative VI has shown a significant increase over 2016
• Labour and UKIP have demonstrated a significant drop in VI over 2016

Analysis by 2015 Voters

• 2015 Labour voters supporting Labour have decreased significantly over the year
• 2015 Labour voters supporting the Lib Dems have increased significantly in the same period
• 2015 UKIP voters supporting the Conservatives have increased significantly over 2016
• 2015 UKIP voters supporting UKIP have decreased over 2016

Look out for part 2, an analysis of the data by region for 2016.