Labour emerged narrowly ahead of the Conservatives in both
the local and European Parliament elections. I discussed the implications of
the local election results in
a previous post on Friday. The results of the Euros only came through last
night. This post considers the lessons
learnt from both elections for the general election, including the likely
accuracy of the opinion polls.
The shares of the vote in Table 1 below are all comparable
in the sense that they all regard voting across Britain as a whole. There are
some methodological issues that explain differences (e.g. locals figures are
projections from parts of England to the rest of GB; polls are polls and not
votes) but the main differences are due to the kind of election.
People vote differently in locals, European and general
elections. Not only is it wrong to suggest that either the local or Euro
election vote share is a forecast (or even nowcast) of the general election, it
was not even possible to tell what the European election result was going to be
from the (earlier-released) local elections on the same day.
Table 1. Percentage
shares of GB vote 2014
|
2010 GE
vote
|
Locals PNS
|
Locals NEV
|
Euros vote
|
GE polls
|
Con
|
37
|
29
|
30
|
23.9
|
32
|
Lab
|
30
|
31
|
31
|
25.4
|
35
|
LD
|
24
|
13
|
11
|
6.9
|
9
|
UKIP
|
3
|
17
|
18
|
27.5
|
14
|
Green
|
1
|
|
|
7.9
|
4
|
Other
|
5
|
10 (inc Grn)
|
10 (inc Grn)
|
8.4
|
6
|
|
|
|
|
|
|
Lab lead over Con
|
-7
|
+2
|
+1
|
+1.5
|
+3
|
|
|
|
|
|
|
PNS: BBC Projected
National Share of the vote
NEV: Sunday Times,
Rallings and Thrasher National Equivalent Vote
Polls: UK Polling
Report Polling Average on election day (22nd May 2014)
The differences between locals, Euros and general election
voting follow a familiar pattern. For most countries, smaller parties do better
and governing parties suffer in European Parliament and local elections
relative to national general elections. These long-established phenomena are
also visible in mid-term general election polls, but much more dramatically in
the local and Euro elections.
In Britain, since at least 1999, more Eurosceptic parties (especially
UKIP but also the Conservatives) have tended to do rather better in the
European elections than in the local elections on the same day. Conversely, as
the most pro-European major party, the Liberal Democrats have typically done
much worse in European than general elections or local elections where they do
best. This pattern was repeated again, probably more strongly, this year. It is remarkable that the UKIP share of the
Euro vote was a full 10 points higher than the average of the estimates of the
local election vote share (PNS and NEV).
Such and other differences between local, European and
general election voting behaviour suggest general election vote intention polls
are a better guide to the next general election vote share than either local or
European election shares. But there are still some lessons from the elections both
directly for the general election next year and for our interpretation of the
opinion polls.
Protest voting and
government recovery?
There is a tendency in Britain for governments to recover
from mid-term setbacks. While in some respects 2009 provides a good example and
basis for comparison with 2014 (both saw Euro and local elections a year before
the general election) it may be an extreme case given the MPs’ expenses crisis
broke during the campaign.
Nonetheless, the pattern of change in Table 2 is indicative
of a more general one from other election cycles. It shows that a government
recovery can be substantial. Gordon Brown managed to claw back a full 7 points
in the year before the general election.
Table 2. Percentage
shares of GB vote 2009: Local and Euro elections, and General Election opinion
polls (with 2005 and 2010 GE)
|
2005 GE
vote
|
Locals PNS
|
Locals NEV
|
Euros vote
|
GE polls (May 09)
|
2010 GE
vote
|
Con
|
33
|
35
|
35
|
27.8
|
39
|
37
|
Lab
|
36
|
20
|
22
|
15.7
|
23
|
30
|
LD
|
23
|
26
|
25
|
13.8
|
19
|
24
|
UKIP
|
2
|
10
|
10
|
16.5
|
9
|
3
|
Green
|
1
|
|
|
8.6
|
|
1
|
Other
|
5
|
9
(inc Grn)
|
8
(inc Grn)
|
17.6
|
10
(inc Grn)
|
5
|
|
|
|
|
|
|
|
Lab lead over Con
|
+3
|
-15
|
-13
|
-12.1
|
-16
|
-7
|
|
|
|
|
|
|
|
PNS: BBC Projected
National Share of the vote
NEV: Sunday Times,
Rallings and Thrasher National Equivalent Vote
Polls: Rallings and
Thrasher polling average for month prior to election day (4th June
2009)
Labour’s recovery halved the lead of the Conservatives
between 2009 and 2010. Although the
levels of the Conservative and Labour vote shares are rather different in the
polls, locals, and especially the Euros, the Conservative leads over Labour are
more similar and tell the same story: mid term setback followed by government
recovery, albeit not a big enough one to secure re-election.
Polling accuracy
One reason why some commentators look to local and Euro
elections provide an insight into the prospects of the parties for the next
election is that they are, so the cliché runs, real votes in real elections.
But opinion polls still provide the best guide. The question then is whether local and Euro
elections tell us anything about the likely accuracy of the polls at the
general election?
For good reasons, there were no attempts (I know of) by
pollsters to forecast a national local election share of the vote. The European
elections, however, provide the only opportunity before the general election to
assess the ability of the pollsters to forecast the share of the vote in a Britain-wide
election.
There is an excellent polling post-mortem by Anthony Wells
with the detailed figures here. Some of the
newer internet pollsters hugely overestimated UKIP (by 3 or more points). There were no telephone polls so we cannot
say whether they would do any better. (They
were not statistically significantly better or worse in 2010.) But clearly
some of the higher estimates of the UKIP share in general election vote
intention polls in recent years seem to be problematic in light of the Euro
results.
Perhaps most importantly for the general election, all of
the final Euro polls (apart from ICM) over estimated Labour and under estimated
the Conservatives. The average
(including ICM) of the six polls put Labour 0.8 points too high and the Tories
1.8 points too low. All suggested Labour leads of at least 3 points. More
commonly the lead was 4 points, with the highest up to 7 points. The actual lead was just 1.5 points.
If this kind of bias occurs in the polls in the run up to
general elections it could be seriously misleading as to the likely outcome.
Even though the polls did not under-estimate Labour in 2010, it was one of just
two elections since 1974 where they did not, perhaps because it was one in
which Labour were at an historically low point.
The polls did overestimate the Tories in 2010, and in every other
election since 1974 apart from 1992.
So the direction of the bias in this year’s Euro opinion polls
fits a long-standing tendency. Table 1 above also provides some indication that
there may currently be a pro-Labour bias in the Labour lead in general election
vote intention in the polls. Whereas the Labour leads in the PNS, NEV and Euros
were between 1 and 2 points, that in general election vote intention is 3
points. Well within the bounds of
statistical significance and the polls have varied, but the difference is in a
direction that suggests a traditional bias might currently be in operation.
Putting the
government recovery and polling bias phenomena together
My
long-range general election forecasting model assumes that future bias in
the polls is more likely to be what it was on average in the past than to
completely disappear in 2015. As a result the forecast is for a larger forecast
Tory lead in 2015 than one would expect just from the tendency for governments
to recover and oppositions to fall back in the final months.
Based on the general election voting intention polling
average in the table above, my forecasting model suggests the Conservatives are
likely to emerge with a clear lead in the share of the vote and 60% chance of
being the largest party in Parliament.
The performance of the Conservatives and Labour relative to
each other in the opinion polls and elections last week provides more comfort
than concern for quality of the model. Chris
Prosser’s model forecasting general election results from local election
results alone produces a remarkably similar forecast share of the vote.
The biggest risk for the model is not so much that UKIP
might get a very large share of the vote in 2015: they are already forecast to
get 12%. Rather it is the (broadly)
uniform national change assumption that looks like potentially being the
weakest link.
One key question is which of the two main parties UKIP will
take votes of more in the key marginals compared with overall. As discussed here,
it currently looks like the overall damage to the two main parties from UKIP is
roughly equal. Even if it was not, the overall hit is reflected in the overall
share of the vote and so in the uniform change projections. More importantly,
there was no evidence in the local election results that the swing between the Conservatives
and Labour was any different in marginal constituencies to elsewhere.
The second question is whether UKIP can mount successful
campaigns to win particular constituencies. Even on the basis of their stunning
results last week, it will be difficult for them to win more than a dozen, or
even a handful, of seats in the Commons.
The party has proved its ability to organize, but the UKIP vote is
geographically less flat, but even in this year’s elections their highest peaks
were still lower than those of the main parties.
Acknowledgements: Thanks to the BBC, John Curtice, Rob
Ford, Jon Mellon, Rosie Shorrocks, and Michael Thrasher for their help with
both data and analysis.