Local elections

Understanding the Local Elections Projected National Share (PNS) in 2023

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by John Curtice and Stephen Fisher, 3rd May 2023.

Much of the speculation about what might happen in the English local elections this week has focused on how many seats each party could or should gain or lose. The Conservatives have seemingly accepted an analysis for the Local Government Chronicle that they could lose 1,000 seats – presumably in the hope that they will do better than that – while Labour have suggested they might win 400 – presumably anticipating they will gain rather more. 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 single or 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, 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.

These caveats are particularly important this year. Ninety per cent of the seats were last fought in May 2019, when Theresa May was Prime Minister and Jeremy Corbyn Leader of the Opposition, both of whom were rebuffed by voters in the local ballot boxes. In contrast, the Liberal Democrats and the Greens performed relatively well four years ago. Meanwhile, just over 5,000 of the 8,000 seats at stake are in relatively small shire district councils, where in most instances all of the seats are up for grabs in wards that elect more than one councillor at the same time. The outcome in these districts will dominate the headline numbers. Moreover, in many instances they are places where Labour is not competitive locally, and the scale of any Conservative losses will depend not on how well Labour do but, rather, on the performance of the Liberal Democrats.

Yet we cannot assess the party’s votes by simply adding up the votes cast (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. For example, unlike last year, there are no elections in Labour-dominated London.

Given all these limitations, a key indicator of party performance that has come to be part of the ritual of local election night (or the following day) 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 if, across Britain as a whole, voters had behaved in the same way as those who did vote in the wards that were contested by all three principal parties in this year’s English local elections. 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 local elections over the last forty years – 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.

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Forecast updates, Local elections

Local elections seat projections for 2023

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By Stephen Fisher, 2nd May 2023.

Changes in vote intention opinion polls typically provide an indication of headline net seat changes at local elections. This year presents a significant challenge to that idea. 

Most of the seats up this year were last fought in 2019. The following table shows how party support in the opinion polls has changed since then.

Table 1. Opinion poll changes from 2019 locals to 2023 locals

%2019 polls2023 pollsChange
Con2929–
Lab3344+11
LD910+1
Brexit+UKIP+Reform196-13
Green55–

With little net change for the Conservatives, Liberal Democrats or Greens, there has been a big swing from the parties which Nigel Farage once led (UKIP, Brexit and Reform) to Labour. We know from surveys that is not the product of much direct switching from Farage parties to Labour. Most of the support for UKIP and the Brexit Party from the spring of 2019 went to the Conservatives by the general election that year. Labour’s more recent rise of support has come disproportionately from 2019 Conservative-Remain voters, even though in absolute terms there have been more Conservative-Leave voters switching to Labour. Also, some of the Labour rise is apparently due to the decline in the numbers of people telling pollsters they know whom they would vote for.

Before thinking about how those general election vote changes might affect local elections this time, we need to reflect on a puzzle from last time. Back in 2019, the Farage parties did not stand many candidates. Many of their supporters must have turned up to the polls but had to look elsewhere for someone to vote for. That was perhaps part of the reason why independents and candidates for micro parties did so well that year. If so, then maybe the independents will do much less well this time now the Farage parties are less popular. But those independents and others who were elected in 2019 might since have built up personal support and benefit as first-term incumbents.

If the rise of Labour in the polls is, to an unusual extent, due to the rise of “Don’t Knows”, it might not translate to gains at the local elections. At around a third of the electorate, local election voters are more engaged and partisan. The rise of the “Don’t Knows” may have been more limited among those who normally vote in local elections. If so, the swing to Labour in the local elections might be smaller than what the polls suggest. 

In addition to those unusual factors, there are the usual reasons why poll swings do not necessarily translate into local election outcomes, especially local politics and selective candidature. 

Nonetheless, I have applied my usual local election seats forecasting models regardless. If nothing else it is interesting to consider the extent to which local election results do track opinion polls, and analysis of the discrepancies is instructive.

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General elections

Why governments lose: UK elections since 1922

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By Stephen Fisher, 12th April 2023.

Governments in the UK tend to win elections, but lose if there is an economic crisis. That pattern explains the outcomes of 19 out of the 27 elections since 1922. A further three elections can be accounted for by governments averting electoral disaster by changing prime minister after a crisis. The combination of economic crises and political changes at the top can explain 22 of the 27 elections, including all the elections since 1987.

That is the main conclusion from my recent working paper. A simplified version of the key table from the paper is shown below. The first row shows that governments won 10 of the 13 elections that were not preceded by an economic crisis. Governments tend to win these elections because governments have a lot of power in Britain. The three elections that were lost without a crisis were all extraordinarily early elections that should not have happened. The 1923 and 1951 elections were gambles, needlessly called by a majority government. To make things worse, on both occasions the government was offering an unpalatable economic policy (tariffs and rationing respectively). The third, 1924, only happened because 1923 produced a seriously hung parliament. None of the three are serious challenges to the idea that governments ordinarily win elections.

 Post-Crisis Political Change of PMGovernment wonGovernment lostTotal
No economic crisisNo10 (1935, 1955, 1966, Oct 1974, 1987, 2001, 2005, 2015, 2017, 2019)3 (1923, 1924, 1951) 13
Economic crisis since the last electionNo2 (1950, 1983)9 (1929, 1931, 1945, 1964, 1970, Feb 1974, 1979, 1997, 2010)11
 Yes3 (1922, 1959, 1992)03
Total 151227 
Table: Economic crises, post-crisis political changes of PM and government electoral fortunes

The bottom two rows of the table show what happened after economic crises. For pragmatic reasons, economic crises are identified by recessions and devaluations from fixed exchange rate systems (such as Wilson’s 1967 devaluation and the 1992 ERM crisis). Unemployment, inflation, strikes and other economic problems still matter, but recessions and devaluations are used because they are indicative of broader crises. 

Out of the 14 post crisis elections, the government lost 9. Using polls, and by-elections before there were polls, the paper sets out how, in each of the 9 cases, the economic crisis contributed to the eventual electoral defeat of the government.   

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Local elections

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

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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.

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Local elections

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

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by John Curtice and Stephen Fisher, 4th 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:   
 ConLabLDOtherConLabLDOtherConLabLDOth
20132629143125291432-100+1
20143031112829311327 -10+2-1
20153631102335291125-1-2+1+2
20163233142130311524-2-2+1+3
20173928181537281817-200+2
20183736141335351614-2-1+2+1
20193131172128281925-3-3+2+4
20214030151536291718-4-1+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. 

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Forecast updates, Local elections, Scotland, Wales

Forecasting Local Election net seat gains/losses 2022

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by Stephen Fisher, 3rd May 2022.

There are local elections tomorrow in England, Scotland, and Wales. Table 1 below shows my forecasts for net seat changes for each. They are based on projecting changes in opinion poll performance since the last round of local elections, with different methods for the different countries as discussed below. They represent what we might expect if the changes in party performance in local elections are on par with changes in the opinion polls.

Table 1. Forecasts for English local election net seat gains/losses for 2022

EnglandWalesScotlandOverall
Con-165-80-36-281
Lab+140+80+84+304
LD+700+6+76
PC 0 0
SNP  -24-24

The Conservatives are expected to lose seats in all three countries. They are defending a strong 2017 base in Scotland and Wales, and dropped in the polls since both 2017 and 2018 when the English seats were last fought. 

Labour are expected to be the main beneficiaries from Conservative losses. The projections suggest Labour might recover most but not all the losses they suffered in 2017 in Scotland and Wales. In England, Labour are trying this week to build on cumulative gains from 2010, 2014 and 2018. They already control over half the seats up this year. Since Labour are at 40% in the polls, their poll support is no greater than is was in 2018. Instead of gaining seats from winning more voters, Labour are projected to make council seat gains in England primarily from the drop in the Conservative vote. But, as discussed below, last-year’s experience shows there are various reasons why that might not happen. 

Perhaps most surprising of the forecasts is the projected drop in SNP seats from what was considered a disappointing performance in 2017, winning only 32% of the first-preference vote when typically the party has been winning at least 45% of the vote in Scotland-wide elections since the independence referendum in 2014. My projection for the Scottish locals this week is based on changes since 2017 in local-election first-preference vote intention polls. Even general-election vote-intention polls show no advance on 2017 for the SNP. The party will be hoping that more of the people who vote for them in Westminster and Holyrood elections will support them in the locals this week. 

England

Typically, the Conservatives lose English council seats when their lead over Labour in the opinion polls drops from what it was the last time the election was fought. Similarly, if the Tories extend their lead, then they typically make net gains. The graph below shows that pattern for local elections in England when the Conservatives were in government and the local elections were not on the same day as a general election. There is a strong correlation, but with a lot of noise around it, meaning any forecast comes with a big range of uncertainty. This year either of the two main parties could be either up or down by more than 100 seats based on the variation in previous local elections.

Last year’s local elections contributed to that noise. The graph above distinguishes between what happened in the elections that were delayed from 2020 because of the Covid pandemic, and those that happened in 2021 as scheduled. The Conservatives substantially outperformed expectations from the historical pattern for both sets of elections. They made +248 gains in the “2020” set despite polls (in 2021) showing only a 1-point increase in the Con-Lab lead since 2016. For the 2021 set, the Tories suffered a net loss of only 14 seats despite the poll lead dropping by 13 points from the high that Theresa May enjoyed in the 2017 local elections (before losing most of it at the general election the following month).

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2019 General Election, Brexit

What impact did the Brexit Party have in the 2019 general election?

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by John Curtice, Stephen Fisher and Patrick English

One of the most dramatic developments during the campaign for the December 2019 general election, whose second anniversary is this weekend, was the decision announced by Nigel Farage on 11 November that the Brexit Party would not contest those seats being defended by the Conservatives. Instead it would concentrate its firepower on those seats currently in the hands of one of the opposition parties. This represented a substantial retreat for a party that just the previous May had topped the poll in the European elections.

But was the decision as important as it was dramatic? Part of the answer to that question depends, of course, on the impact the decision had on the overall popularity of the party where it was continuing to fight. It almost certainly helped to reduce it. In the week leading up to Mr Farage’s announcement, the Brexit Party stood on average in the polls at 16% among those who had voted Leave in the 2016 EU referendum. (It had no measurable support at all among Remain supporters.) A week later, its support among Leave voters had fallen by five points to 11% (while support for the Conservatives was up by five points). By polling day, the party was down to just 4%.

Of course, much of this drop would have been occasioned by the gradual realisation among voters in the relevant seats that the Brexit Party was not standing locally, though the scale of the drop by polling day is too big to be explained by that alone. Equally, some voters will have switched away from the party for reasons that had nothing to do with Mr Farage’s decision. But it certainly looks highly likely that the Brexit Party’s partial withdrawal helped to undermine its level of support where it continued to stand.

Even so, the party still managed to win an average of 5.7% of the vote in those seats in England & Wales that it did fight – potentially enough to have some impact on the relative fortunes of the other parties. But what impact did it have? Mr Farage’s decision appeared to reflect his oft made claim that his party was able to gain the support of voters in Labour-inclined, more working class constituencies that the Conservatives could never reach. Thus, while standing down in Conservative-held seats might help avoid a split in the Leave vote that could help the opposition parties to gain Conservative-held seats, continuing to contest opposition-held seats might help the pro-Brexit Conservatives to gain Labour-held seats and thus the overall majority that Boris Johnson was seeking.

The success or otherwise of this strategy is addressed in our analysis of the constituency election results in the recently published ‘Nuffield’ study of the last election, The British General Election of 2019. It proved far from an easy question to answer.

We could, of course, look at the choices that those who voted for the Brexit Party in 2019 had made at the previous election two years earlier. In fact, according to the 30,000 sample British Election Study internet panel (BESIP), rather more Brexit Party voters had voted Conservative (40%) than Labour (30%) in 2017, suggesting that there was little truth to Mr Farage’s assertion that this party was particularly effective at winning over Labour voters in Labour constituencies. However, what matters here is not how Brexit Party voters voted in 2017, but how they would have voted in the absence of a Brexit Party candidate in 2019.

One way of trying to address this counterfactual question is to compare the performance of the parties where the Brexit Party did and did not stand. At +5.3%, the swing from Labour to Conservative since 2017 was rather higher in seats (In England & Wales) that the Brexit Party contested than it was is those seats that it did not (+4.7%). That suggests that the presence of a Brexit Party candidate did do Labour somewhat more harm than the Conservatives, an observation apparently reinforced by the fact that the swing to the Conservatives tended to be higher the bigger the Brexit Party’ share of the vote.

But if the Brexit Party were winning over Labour voters who would never back the Conservatives, we would anticipate that Labour would have lost support more heavily among Leave voters in seats where the Brexit Party stood than it did in those that it did not. Yet the BESIP data suggest that, if anything, the opposite is true. In seats where the Brexit Party stood, 57% of those who voted Leave in 2016 and Labour in 2017 voted for the party again, compared with just 48% in seats the Brexit Party did not contest. Meanwhile, whereas in those seats the Brexit Party did not contest 39% of Labour Leave voters switched to the Conservatives, in seats where there was a Brexit Party presence only 26% did so. Much of the difference between these two figures is accounted for by the 10% who backed the Brexit Party in seats the party was contesting – suggesting that all the Brexit Party managed to achieve where it stood was to divert the support of Labour Leave voters away from the Conservatives.

This in turn, however, is also probably too bold a conclusion. When the BESIP asked respondents to give both the parties and the leaders a mark out of ten, those Leave voters who switched from Labour to the Brexit Party gave both the Conservatives (3.8) and Boris Johnson (5.3) a lower score than those who switched from Labour to the Conservatives (6.2 and 7.1 respectively), suggesting that perhaps not all of those who switched from Labour to the Brexit Party would have swung behind the Conservatives in the absence of a Brexit Party candidate.

In the absence of data on the second preferences of those who voted for the Brexit Party, we modelled the behaviour of Labour Leave voters in seats that the Brexit Party did not contest (taking into account demographics and evaluations of the parties and leaders) and then applied the resulting equation to those voters who elsewhere switched from Labour to the Brexit Party. This suggested that in the absence of a Brexit Party candidate, 70% of those who switched from Labour to the Brexit Party would have instead backed the Conservatives, while just 30% would have stuck with Labour.

It is on this basis that we conclude that the Brexit Party’s decision to continue to fight opposition held seats cost the Conservatives seats they might otherwise have won. If we apply that 70:30 ratio to the share of the Brexit Party’ share of the vote in each constituency, we find that there are around 25 seats that Labour managed to retain that might otherwise have fallen from its grasp – many of them in the North of England and the Midlands – and enough to give the Conservatives an overall majority of 130.

Meanwhile, because there was a national swing from Labour to the Conservatives anyway, the Brexit Party’s decision to stand down in Conservative-held seats helped save the Conservatives from defeat in at most a small handful of Remain-inclined seats.

The squeeze on Brexit Party support during the 2019 election campaign, a squeeze that was probably accelerated by its decision to vacate the contest in Conservative-held seats, played a role in enabling the Conservatives to unite much of the Leave vote behind it, an outcome that was central to their success in winning an overall majority of 80. Even so, the Brexit Party’s continued presence in seats that the opposition parties were defending still acted as something of a brake on that achievement. Small though its tally of votes might have been, under the first-past-the-post electoral system, it was still enough to make a significant dent in the size of the Conservative majority and in reducing the extent of the breach in Labour’s so-called ‘Red Wall’. Little wonder that, in the wake of the outcome of the Old Bexley & Sidcup by-election, commentators are now wondering what role, if any, the Brexit Party’s successor, Reform UK, might play at the next general election.

This blog is also to be found on the What UK Thinks website.

            The British General Election of 2019, by Robert Ford, Tim Bale, Will Jennings and Paula Surridge is published by Palgrave Macmillan.

Forecast updates, German elections

What do citizens forecast for the 2021 German federal election?

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Guest post by Andreas Murr, University of Warwick.

On Sunday 26 September Germans will go to the ballot box to cast several votes in state and federal elections.  The Economist and several academics have published their federal election forecasts.   But who do Germans think will win the election?  Two research teams have used such citizen forecasts to predict the upcoming federal election.

Murr and Lewis-Beck predict the parties’ national vote shares based on citizens’ responses to the question “Who will win the general election?”  Their prediction is based on a regression model of historical vote shares on citizen forecasts and whether there was a grand coalition.  The historical data goes back until 1980.  Combing their regression model with a recent Politbarometer survey from June, they predict CDU/CSU to win 34% of the vote and SPD to win 21%. of the vote.  According to them, a CDU/CSU/SPD coalition seems the safest bet statistically, though a CDU/CSU-Greens coalition is not out of the question.

Kayser et al. predict both constituency winners and parties’ national vote shares by simply aggregating citizen forecasts collected in a survey the last two weeks.  They collected two different kinds of citizen forecasts.  First, they asked citizens to forecast which candidate will win in their constituency.  And, second, they asked citizens what vote share each party will win nationally.  The authors then simply predict the constituency to be won by the candidate who most citizens say will win.  And, they predict the vote share of a party to be the average of citizens’ forecasted vote share.  In other words, only survey data and no historical data was used to forecast the election.  Citizens collectively predict that CDU/CSU will win more constituencies than the SPD (174 v. 98).  However, they also collectively predict that SPD will win a higher national vote share than CDU/CSU (25% v. 23%).  The Greens are predicted to win 16%.

Why do the forecasts of the two teams differ?  The two teams use different methods and forecast with different lead times.  However, we can update the forecast of Murr and Lewis-Beck by using the most recent Politbarometer survey from mid-September.  This way the forecasts differ only in method.  If we do this, then both forecasts go in the same direction.  The Murr and Lewis-Beck model then predicts CDU/CSU to win 25% and SPD to win 31%.  In other words, their updated model would also predict the SPD to win a majority of the votes, though a bigger one than predicted by Kayser et al.  This said, Murr and Lewis-Beck did some analysis of the optimal lead time of their model: they find that it forecasts more accurately with a lead time of two months (June) than one month (September) on average.  Of course, soon we will know which lead time or method forecasted better in this election.

Local elections, Scotland, Wales

What does it take to get elected in Scotland and Wales?

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By Stephen Fisher, 6th May 2021.

There is speculation about how well various new and small parties will do in today’s elections to the Scottish and Welsh Parliaments. Former SNP First-Minister Alex Salmond has recently established the Alba Party, while George Galloway has created Unity 4 All. Both are contesting regional list seats in Scotland. Meanwhile, Abolish the Welsh Assembly has come fourth, with at least 6% of the regional list vote, in all four polls for the Welsh Parliament (Senedd Cymru) since mid-April. Also, Reform-UK, the renamed Brexit Party, is fielding candidates in both countries. These are just some of the various contenders.

This post explains some of the complications in trying to figure out what share of the vote a party needs to get elected in these institutions. It ends up pointing to past experience as a guide and drawing comparison with and the electoral system for the Greater London Assembly (GLA).  

TLDR: The experience of all five elections to the Scottish Parliament suggests that around 5.5% of a regional list vote is usually enough to win a seat. It would be rare, but not impossible, to miss out on a seat with 6%. Winning on 5.2% to 5.4% is not uncommon. The lowest D’Hondt ratio ever to yield a seat in Scotland was 4.6% (equivalent to a single party winning a seat on that share). That was in 2003 when the SNP won 5 seats, including 2 list seats, with 23.0% of the Mid Scotland and Fife list vote. For the Senedd, a share of around 6.5% in a region is likely to be enough, especially in North Wales and Mid and West Wales which have historically been more accessible to small parties. By comparison, the GLA has a 5% legal threshold, without which parties would get seats with 3.8% of the vote.

Scotland

The Scottish Parliament has 129 seats. The electoral system is sometimes described as proportional, but it is significantly different from pure proportional representation. If it were close then a party would win a seat for roughly every 0.8% of the vote, since 100/129=0.8. More precisely, if all the seats were elected by the D’Hondt method of proportional representation a party would be guaranteed a seat with more than 100/(1+Number of seats) per cent of the vote, that is 100/130 = 0.77% of the vote. As we shall see that is much lower than what is actually required to get elected.

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Forecast updates, Local elections

Forecasting Local Election Net Seat Gains/Losses 2021

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by Stephen Fisher, 6th May 2021.

Local election seat gains and losses are hideous to try to predict at the best of times. Various factors make this year especially hard. The Covid-19 pandemic means that the 2020 round of local elections was postponed to today, and there have been various boundary changes and restructuring that mean it is hard to allocate many seats to either the 2016-2020 or the 2017-2021 4-year cycle that my model requires. Nonetheless, and despite the weaknesses of my 2019 forecast (discussed below), I have ploughed on regardless. This is not due to the kind of stoic determination that the Finns call sisu: amusingly summarised by someone as, “chin down and press on to the next disappointment.” Rather, I am still curious as to how much of a guide (on a broad macro level) Westminster vote intention polls are to local election outcomes. 

Headline forecasts are in the table below together with the range of possible outcomes in the model. The table includes the projections from Michael Thrasher’s second scenario here. He and Colin Rallings would normally calculate an expected National Equivalent Vote (NEV) from the results of local by-elections, but those have not been happening. Instead Michael Thrasher has used adjusted opinion polls to estimate the NEV and then projected the implied changes at the ward/division level. Both mine and his methods use polls this year, but whereas Michael’s is a local projection based on previous ward and division level results, mine is based on regression models of the macro historical relationship between poll changes and net seat changes. (For a really micro, individual-level approach, predicting Labour losses in “red-wall” councils, but not overall net gains and losses, see the analysis from YouGov’s Patrick English here.)

Table 1. Forecasts for English local election net seat changes 2021

ForecastRangeThrasher
Con-210-770 to +350+120
Lab+70-290 to +430-50
LD+140-50 to +330-70
Others0 0

It is striking that my forecasts point in different directions from Michael Thrasher’s projections for every party. But with 4630 odd seats up for election, both sets of predictions are for modest net changes. The prediction intervals for my forecasts comfortably include zero for all three parties, so each of them could easily end either up or down when all the results are in. 

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Election analysis and forecasting