BSPS 29 February Mid-2006 based Subnational Population Projections – Jonathan Swan SPEaQE
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Transcript of BSPS 29 February Mid-2006 based Subnational Population Projections – Jonathan Swan SPEaQE
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
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.