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 • 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 Consultation Contents • Covering Letter • Methodology Paper • Criteria for Changing Assumptions and FAQs • Migration Paper • Links for Further Information • Migration Questionnaire – Part One response – District Level LAs only – Unless disagreement when All LAs, PCOs, Regional Organisations can also respond • Part Two Paper and Annexes – Responses invited from all – Includes list of consultation questions + Data dispatch to LAs inc Counties, PCOs, GORs, SHAs 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.
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