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BSPS 29 February Mid-2006 based Subnational Population Projections – Jonathan Swan SPEaQE. Introduction. Subnational population projections produced every two years Projection by age and sex Projection for every LA in England Based on mid-year estimates Preceded by consultation
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BSPS 29 FebruaryMid-2006 based Subnational Population Projections – Jonathan Swan SPEaQE
Introduction • Subnational population projections produced every two years • Projection by age and sex • Projection for every LA in England • Based on mid-year estimates • Preceded by consultation • Cover 25 years i.e. 2006 based go up to 2031
2006 based Timetable • February 2008 - Calculation of provisional project’s • 6 March - Start of Consultation • 17 April - End of Consultation • April - Analysis of Consultation Responses • Reply to responses • May/June - Final Calculations and QA • June 2008 - (date tba) Main Publication • August 21 - Analysis of Accuracy published • [December 2008 – Earliest date for variants]
Basic Methodology • Cohort Component Method • Pt+1 = Pt + B – D + M • Trend Based Projections • Based on Past Trends • Projections not Forecasts • Do not take account of policy considerations • Top Down • Components Constrained to National Projections • LA as base unit • PCOs by proportional allocation
The Consultation • Part One: • Consultation on Initial Migration Assumptions • Traditionally done every new base year • Consultation with Local, Health, and Regional Authorities only • District Level LA lead. • Part Two • Open to all • Consultation on Outputs • Internet tables / Tables on Request • Variants • Demand and Which variants • Methods to be used
Criteria for accepting change during the consultation • Consultation is focused on the migration assumptions in the first year of projections • Assumptions are based on recent demographic trends • Internal Migration based on past 5 years data from patient register • International Migration based on new MYE methods • Clear evidence required that the level of migration is incorrect before projections are adjusted • Major one-off change in employment situation • Areas with high student populations • Consultation paper has more info.
Criteria for accepting change during the consultation (2) • Dwelling stock plans will not be considered • Unlike GLA, Projections unconstrained by Housing Capacity • New Housing Estates not directly allowed for • Inevitable that projections for small areas are prone to greater uncertainty • Assumptions of fertility and mortality use high quality registration data • Any RELIABLE migration data will be considered – if it shows a different trend
Syndicate Sessions • As consultation not out - Change to 3 groups • Modelling Components (Combined group): • How can we change migration and natural change components to reflect local variation? • How can this be done systematically? • Can/Should this be related to national variant methods? • Which Variants Should we do? • Which are the most important scenarios? • What are the driving needs for variants? • How can we do a housing constrained variant? (new Group) • Which data sources? (Regional plans?) • Using what methodology? • Relationship between housing and population complex.
Rest of day .. • Syndicate Session will be followed by feedback. • Then a chance to discuss issues from the day and ask the panel.