By Stephen Fisher, 6th May 2022.

The BBC Projected National Share (PNS) of the local election vote 2022 is Con 30, Lab 35, LD 19, Others 16.

There is an explainer of the methodology at https://electionsetc.com/2022/05/04/understanding-the-local-elections-projected-national-share-pns-in-2022/.

Historically, party performance in local elections has followed a similar pattern of change over time to the general-election vote-intention opinion polls, as shown the graph below.

Changes in the PNS this year are broadly in line with changes in the polls relative to both 2018 and 2021. The Conservatives are down 7 in the polls since both 2018 and 2021, and down 5 and 6 points respectively in the PNS. Labour are at the same level in the polls and PNS as they were in 2018, but up 4 points in the polls and 6 points in the PNS since 2021. 

In both the polls and the PNS the two parties were tied in 2018. After Boris Johnson became PM the Conservatives achieved a lead that won them the 2019 general election and lasted through to 2021. Following partygate and various other controversies, that lead has been reversed. This week’s local elections essentially confirmed the message from the polls that Labour are now ahead.

In recent years the Liberal Democrats have revived their tendency to do much better in local elections than they do in general election vote intention polls. That pattern was established in the 1980s with the Liberal Alliance, but ended after the Lib Dems joined the coalition in 2010. This year the party continued its post-coalition revival. They are up 2 or 3 points relative to both 2018 and 2021, in both the PNS and the polls.

Its not such a consistent pattern with respect to other baselines.

Indications from the local elections for the next general election?

The Projected House of Commons’ seats from the PNS (with changes from the 2019 general election) is

Con 253 (-112)

Lab 291 (+88)

LD 31 (+20)

Others 75 (+4)

The Projected House of Commons takes into account differences in local and general election voting on recent occasions when the two kinds of election have been on the same day.

Continue reading Local elections Projected National Share (PNS) of the vote 2022 →

by John Curtice and Stephen Fisher, 4^th May 2022.

Much of the speculation about what might happen in the English local elections tomorrow has focused on how many seats each party could or should gain or lose. Indeed, we can expect many a judgement to be cast on Friday on the basis of this evidence. However, given that these elections are held under first past the post (and in London multi-member plurality), seats won and lost can be a poor guide to how well a party has done in the ballot box. A party whose vote has fallen less than that of their principal rivals may gain seats even though it has lost votes. A third party whose vote is geographically spread may make a substantial advance in votes yet reap little reward in terms of seats. Meanwhile, even if these issues do not arise, seats won and lost only provide an indication of whether a party has lost or gained ground as compared with when the seats up for grabs were last contested – which this year, as is usually the case, was four years ago.

Yet we cannot simply add up votes cast either (even if we had the resource to collect them all on election night). In England (unlike Scotland and Wales) it is never the case that the whole country votes in local elections at the same time. The places that vote one year are politically different from those that vote in another. Given all these limitations, a key indicator of party performance that has come to be part of the ritual of local election night is the calculation of a ‘projected national share’ (PNS). This is an estimate of the share of the vote that the principal parties would have won in a GB-wide general election if voters across the country as a whole had behaved in the same way as those who actually voted in the local elections that year in England. It provides a single, seemingly straightforward measure of party performance that can tell us not only how well or badly a party has done as compared with four years ago, but also as compared with any previous local elections for which a PNS is available – even though the places in which local elections are held varies considerably from one year to the next.

Yet almost inevitably answering such a ‘what if’ question is not as straightforward as it might seem. Given the large number of wards being contested, the calculation of the PNS has to be made on the basis of a sub-sample of the local contests. None of the parties fight all of the wards being contested, and some may well fight fewer wards than others. At the same time, local election results in England tell us nothing about the performance of the nationalist parties in Scotland and in Wales. Any estimate of the PNS is affected by the decisions that are made about how best to address these issues. It is thus not surprising that there have often been some differences between the PNS that we have calculated for the BBC at previous local elections and that calculated by the local election experts, Colin Rallings and Michael Thrasher of Plymouth University, whose National Equivalent Vote (NEV) appears each year in The Sunday Times. 

Those differences are typically limited with neither the PNS or NEV consistently better for any party. But since 2015 there has been a tendency for the PNS to be higher for Liberal Democrats and Others, and correspondingly lower for the Conservative and Labour than the NEV series. This can be seen in the table below. 

	NEV:				PNS:				Diff:
	Con	Lab	LD	Other	Con	Lab	LD	Other	Con	Lab	LD	Oth
2013	26	29	14	31	25	29	14	32	-1	0	0	+1
2014	30	31	11	28	29	31	13	27	-1	0	+2	-1
2015	36	31	10	23	35	29	11	25	-1	-2	+1	+2
2016	32	33	14	21	30	31	15	24	-2	-2	+1	+3
2017	39	28	18	15	37	28	18	17	-2	0	0	+2
2018	37	36	14	13	35	35	16	14	-2	-1	+2	+1
2019	31	31	17	21	28	28	19	25	-3	-3	+2	+4
2021	40	30	15	15	36	29	17	18	-4	-1	+2	+3

It is not entirely clear why these gaps have emerged. Here we aim to explain some of the key features of the PNS methodology that might help explain the difference. In doing so, our aim is not to suggest that one approach is better than another, but rather to explain some of the decisions we have made that can have an impact on the figures we publish. 

Continue reading Understanding the Local Elections Projected National Share (PNS) in 2022 →