W5 Local elections and national polls: modelling change

[W5.1 PART 1 The first two sections]

[W5.2 PART 2 Sections 3 to 8]

[W5.3 PART 3 The main part, Section 7.2]

PART 1 The first two sections

Abstract

1 Introduction

2 A simple account

2.1 This week’s by-elections: the headlines

2.2 Six recent by-elections

2.3 A simple model

2.4 Beyond the simple model

2.5 Conditional statements about the next general election

PART 2 Sections 3 to 8

3 Regions and constituencies: density-dependent survival rates?

4 How the vote changes: percentage change, step ratio or change in z-score?

5 Scotland parliamentary elections: SNP and LibDem step ratios, 2007 - 2011

6 Local government elections, 4th May 2023 … step ratios

7 Local by-elections

7.1 George Galloway and Bradford West, March 2011

7.2 The main part … England: the ‘historic’ by-elections, 20th July 2023

… see Part 3

7.3 Scotland: SNP loses Rutherglen, 5th October 2023

7.4 England: another two losses, 19th October 2023

8 Conditional statemen

PART 3 The main part, Section 7.2

England: the ‘historic’ by-elections, 20th July 2023

1 Introduction

Part 3.1 Statics - the situation at one point in time: 2019

Part 3.2 Change

Part 3.3 Flow

Part 3.4 Political space (not yet available)

Part 3.5 The distribution of size (not yet available)

Part 3.6 Gravitational flow (not yet available)

1 Introduction

The ‘historic’ by-elections, 20th July 2023

Sources

Part 3.1 Statics - the situation at one point in time, the 2019 general election

The seats

“The people” … the sets of individuals

The candidates in 2019

The results in 2019

Individual preferences and the social choice mechanism output

The winner and the ordering of the parties

The size distribution

The size distribution as a consequence of a spatial distribution

The parties in political space, July 2023

The distribution of size in political space

Part 3.2 Change

2 Measures of change

3 The results, national and local

The winner and the ordering of the parties, 2019 and 2023

National change: the 2019 general election and the July 2023 polls

Local change: Uxbridge, Frome and Selby; 2019 and 2023

General and specific volatility: the results

4 Changes in the Conservative vote

Measures of change in the Conservative vote: difference, swing and step ratio

Predicting the local Conservative vote using the national measures

Part 3.3 Flow

5 The flow of individual voters

6 Flows between Conservative and Other

Staying Conservative: the survival rate, 2019 to 2023

Becoming Conservative: flow/transition rates, 2019 to 2023

Conservative and Other: the 2x2 transition matrix

The national 2x2 transition equations, 2019 and 2023; local ‘predictions’

Using the transition matrix to predict the Nadine Dorries Mid-Bedfordshire by-election

7 Flows between the individual parties

Staying with the party: the national survival rates for the other two main parties (2019GE – July 2023)

The transition rates for the three main parties

The three main parties: the transition matrix

The national 3xn transition equations, 2019 and 2023, local ‘predictions’

Part 3.4 Political space                    (not yet available)

Part 3.5 The distribution of size      (not yet available)

Part 3.6 Gravitational flow             (not yet available)

Gordon Burt, 22nd October 2023

THE END