Transcript Utilising population projections for local authority strategic planning (with notes) Stuart Booker Financial Planning and Research Team Fife Council BSPS Annual Conference University of Southampton 18-20 September 2006

Utilising population projections for
local authority strategic planning
(with notes)
Stuart Booker
Financial Planning and Research Team
Fife Council
BSPS Annual Conference
University of Southampton
18-20 September 2006
Overview
• Context
• National data sources
Quantitative analysis of GAD/GROS projections for Fife
Conclusions
• Fife Council data sources
Comments on Fife Council and other data
• Future work
How to synthesise information for strategic planning?
Context
• Fife is Scotland’s third most
populous local authority
Glasgow City
Edinburgh, City of
Fife
578,790
457,830
356,740
…
Eilean Siar
Shetland Islands
Orkney Islands
SCOTLAND
26,370
22,000
19,590
5,094,800
• Fife covers a geographical area
of 512 sq. m.
• Fife has significant rural
and urban populations
Context
• The Edinburgh economy has a
significant impact on Fife
• Fife’s share of the Scottish
population is increasing
Fife
1995
2005
Fife
Scotland Share
(%)
349,720 5,103,690
356,740 5,094,800
6.85
7.00
• Fife public services operate to
a common boundary, including:
Council, Health Board, Police
Force, Waste Plan Area ...
• Fife has well developed
community planning
FPR Requirements
Aim: to understand Fife’s future population to allow strategic
planning of Fife Council (and Partnership) services
Income
Expenditure
Aggregate External Finance
Fife share of key client groups
Service demand
Size of key client groups
Number of households
Council Tax
Number of households
Household composition
Three year settlement
Population projections
Unit cost
Other client group trends
Other household trends
Fife Council Requirements
Present use of population data
GROS projections
Fife Council
Education
Service
Planning
Service
School roll
projections
Structure
Plan
Other
Services
ScotXED
pupil data
Service
planning
National Data Sources
General Register Office for Scotland (GROS) projections
• GAD (ONS) UK projections made every two years
• GROS produce variant projections for Scotland
• GROS produce projections for local authority areas (32) and health boards (15)
Advantage
• Provides self-consistent figures at local authority level across Scotland
necessary for projecting resource distribution in future years
Disadvantage
• No projections available below local authority level
necessary for planning future service delivery at a local level
Issues
• Migration assumptions and migration data volatility
National Data Sources
General Register Office for Scotland (GROS) projections
Projected Fife total population
400,000
375,000
350,000
325,000
2002 based projection
2018
2016
2014
2012
2010
2008
2006
2004
300,000
2004 based projection
Question: are the GROS projections sufficiently reliable
for strategic planning of Council services?
National Data Sources
General Register Office for Scotland (GROS) projections
Method: quantitative analysis of GROS projection methodology
• Spreadsheet cohort-component model of Fife population
• Using GAD/GROS implementation
• Using GAD published fertility/mortality rates
• Using local scaling factors for Fife published by GROS
• Using age-sex migration data for Fife supplied by GROS
• Validated against principal and variant projections for Scotland
Note: not reconciled back to Scottish national total
Variant projections for Fife
Fertility: method
Local scaling factor
for Fife
Principal or
variant fertility
rates
Scotland fertility
rates by year
and age
Cohort component
model
Projection
by year and age
The same method has been used to produce variant projections for high
and low life expectancy.
Variant projections for Fife
Fertility: results for high fertility projection
Principal projection
Age
Band
High fertility
2004
2024
2004
2024
population population population population
Difference by 2024
Difference
(number)
Difference
(%)
0-4
5-11
12-17
18-34
35-49
50-64
65-69
70-74
75-79
80-84
85-89
90+
18,715
29,420
27,804
72,921
79,798
67,292
17,146
14,577
11,765
8,814
3,977
2,371
20,622
29,084
24,195
75,367
70,559
78,968
23,069
20,102
19,044
12,649
7,956
5,119
18,715
29,420
27,804
72,921
79,798
67,292
17,146
14,577
11,765
8,814
3,977
2,371
23,046
32,684
26,753
75,511
70,559
78,968
23,069
20,102
19,044
12,649
7,956
5,119
2,424
3,600
2,558
144
0
0
0
0
0
0
0
0
11.8
12.4
10.6
0.2
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Total
354,600
386,734
354,600
395,460
8,726
2.3
High fertility projection: TFR of 1.8
Principal projection: TFR of 1.6
Fife local fertility factor: 1.019
Variant projections for Fife
Fertility: results for high fertility projection
Principal projection
High fertility
Change (%) 2004 to 2024
140.0
120.0
100.0
80.0
60.0
40.0
20.0
0.0
-20.0
0-4
5-11 12-17 18-29 30-44 45-59 60-74 75-89
90+
Total
Note: continuing decline in population of secondary school age
Variant projections for Fife
Mortality: results for high life expectancy projection
Principal projection
Age
Band
High life expectancy
2004
2024
2004
2024
population population population population
Difference by 2024
Difference
(number)
Difference
(%)
0-4
5-11
12-17
18-34
35-49
50-64
65-69
70-74
75-79
80-84
85-89
90+
18,715
29,420
27,804
72,921
79,798
67,292
17,146
14,577
11,765
8,814
3,977
2,371
20,622
29,084
24,195
75,367
70,559
78,968
23,069
20,102
19,044
12,649
7,956
5,119
18,715
29,420
27,804
72,921
79,798
67,292
17,146
14,577
11,765
8,814
3,977
2,371
20,641
29,096
24,195
75,407
70,639
79,287
23,271
20,338
19,397
13,022
8,344
5,646
19
12
0
40
80
319
202
236
353
373
388
527
0.1
0.0
0.0
0.1
0.1
0.4
0.9
1.2
1.9
2.9
4.9
10.3
Total
354,600
386,734
354,600
389,283
2,549
0.7
High life expectancy: 81.4 (males) and 85.1 (females) at birth in 2031
Principal life expectancy: 79.1 (males) and 83.6 (females) at birth in 2031
Fife local mortality factor: 0.928 (males) and 0.939 (females)
Variant projections for Fife
Mortality: results for high life expectancy projection
Principal projection
High life expectancy
160.0
Change (%) 2004 to 2024
140.0
120.0
100.0
80.0
60.0
40.0
20.0
0.0
-20.0
-40.0
0-4
5-11 12-17 18-29 30-44 45-59 60-74 75-89
Note: significant increase in oldest age groups
90+
Total
Variant projections for Fife
Migration: method
• The age-sex structure for migration varies significantly across Scotland
• Use long term migration assumption from 2002 based projection
• Reflects age-sex structure of local authority for (relatively) recent conditions
Note: can also look at natural change
Variant projections for Fife
Migration: difference in assumption between 2002 and 2004
Assumed long-term net migration Fife council area: Females
200
150
Assumed net migration
100
50
0
-50
-100
-150
0
3
6
9
12
15
18
21
24
27
30
33
36
39
42
45
48
51
54
57
60
63
66
69
Age
Females 2004-based
Females 2002-based
72
75
78
81
84
87 90+
Variant projections for Fife
Migration: results for 2002 based migration
Principal projection
Age
Band
2002 based migration
2004
2024
2004
2024
population population population population
Difference by 2024
Difference
(number)
Difference
(%)
0-4
5-11
12-17
18-34
35-49
50-64
65-69
70-74
75-79
80-84
85-89
90+
18,715
29,420
27,804
72,921
79,798
67,292
17,146
14,577
11,765
8,814
3,977
2,371
20,622
29,084
24,195
75,367
70,559
78,968
23,069
20,102
19,044
12,649
7,956
5,119
18,715
29,420
27,804
72,921
79,798
67,292
17,146
14,577
11,765
8,814
3,977
2,371
16,573
24,722
22,151
68,346
64,196
77,792
23,026
20,133
19,064
12,592
7,895
5,028
-4,049
-4,362
-2,044
-7,021
-6,363
-1,176
-43
31
20
-57
-61
-91
-19.6
-15.0
-8.4
-9.3
-9.0
-1.5
-0.2
0.2
0.1
-0.5
-0.8
-1.8
Total
354,600
386,734
354,600
361,518
-25,216
-6.5
Question: if a 5% difference between projections is significant,
when does the earliest significant difference occur?
Variant projections for Fife
Migration: earliest significant difference between projections
Earliest year at which error exceeds threshold
(total population)
2025
Year
2020
2015
2010
2005
0
10
20
30
40
50
Age
60
70
80
90 &
over
Note: this type of approach
allows a useful timescale
to be put on the set of
projections in question
National Data Sources
Summary (recording all differences from principal projection > 5%)
High life
expectancy
Low life
expectancy
Low fertility
High
fertility
Alternative
migration
0-4




(-12.2%)

(-10.9%)

(-7.5%)

(11.8%)

(12.4%)

(10.6%)




35-49





(-19.6%)

(-15.0%)

(-8.4%)

(-9.3%)

(-9.0%)
5-11


12-17

18-34
50-64





65-69





70-74





75-79





80-84





85-89





Age band
90+
Total
population


(-9.8%)
(10.3%)








(-6.5%)
Fife Council Sources
School roll projections
• Fife Council Education Service produces school roll projections
• Based on recent trends and placing requests
• Uncertain how well trends capture recent increase in housing stock
• Two projections produced at present
• A ‘trend-based’ projection
• A ‘strategic’ projection, including an additional allowance for new housing
• There is a notable agreement between the school roll projections
and two variant projections for Fife (principal and alternative migration)
• Agreement for primary pupils is slightly better than that for
secondary pupils
Fife Council Sources
Comparison of school roll projections with Fife variant projections
School roll 'strategic' projection
Trend-based school roll projection
GROS principal projection
'Alternative' migration projection
30,000
26,000
24,000
22,000
Year
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
20,000
2004
Pupil numbers
28,000
Fife Council Sources
Use of council sources to produce projections at
• School roll projections are produced at school catchment and
area (former district council) level
• School roll projections provide a way to relate future changes in
the pre-school and school age population to projections at the
Council area level
• Information of the local housing requirement
Future Work
How to synthesise information for strategic planning?
Fife Council data
GROS projections
NHS data
Measures to assess
utility of GROS
projections
Fife Partnership
projections
e.g. Popgroup
Coherent view of
population change in Fife
and Scotland as a whole