Local Population Projection in practice David CULLUM Deputy Manager Research Team November 2009
Jun 24, 2015
Local Population Projection in practice
David CULLUMDeputy Manager
Research TeamNovember 2009
•Why did we do our own local projection?•How did we do it?•What did our local projection tell us?•What are we doing with our local projection?
Why did we do our own local projection?
ONS a top-down ‘disaggregation’ of national projections
ONS based on past 5 years trend – which were anomalous for Gloucestershire
Significant differential between ONS MYE and our own local estimates
Why did we do our own local projection?
ONS based on past 5 years trend – which were anomalous for Gloucestershire
•Historically high levels of housebuilding•Significant influx of A8 migrant workers•Also, 5-year ‘trend-based’ projections are ‘policy-blind’
Why did we do our own local projection?Significant differential between ONS MYE and our own local estimates
•ONS say 582,600 for mid 2007•We reckon 594,700•Based on GP registrations/electoral registers
How did we do it?We used POPGROUP© with
•Local population base•Local fertility rates•Local mortality rates•Local migration estimates•Residential development plans (RSS)
How did we do it?Local population base•12,000 higher than ONS MYE at mid 2007
-500
0
500
1,000
More in GCC
More in ONS
Very young Very old
How did we do it?Local fertility & mortality rates
•Locally observed fertility and mortality rates•Provided by Glo’shire NHS•Future vital trends modelled using GAD estimated rates
How did we do it?Local migration estimates
Used ONS District inflow/outflow data to derive rates for internal (within UK) migration
International Migration based on:•NINO•Migrant Worker study for length of stay•High levels of A8 in-migration in short term, ‘decaying’ to EU norm for Glo’shire after 10 years
How did we do it?Residential development plans (RSS)
•Draft Regional Spatial Strategy housing targets for Districts•51,000 houses in County 2008-2026•Annual targets for each district input into projection model•Significant policy influence
What did our local projection tell us?
540,000
560,000
580,000
600,000
620,000
640,000
660,000
680,000
2007 2012 2017 2022
Local Projection
ONS projection
What did our local projection tell us?
Local growth rate 8.8%ONS rate 13.7%
What did our local projection tell us?
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85plus
our projection
ONS 2006 based
Projected population 2026
What did our local projection tell us?
ONS projecting a more elderly population
More people of parenting age in our local projection
What did our local projection tell us?
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85plus
our projection
ONS 2006 based
Projected population 2026
What are we doing with our local projection?
What are we doing with our local projection?
What are we doing with our local projection?
80
85
90
95
100
105
110
115
120
125
130
2007 2012 2017 2022
2007=100
Young Offender projections 2007 to 2026
CheltenhamCotswoldForest of DeanGloucesterStroudTewkesbury