1. The Cohort-Component Method A new Method for Household Projections by Tenure Jan Freeke Glasgow City Council

2. Existing Methods (1) Structure Plan – Private sector housing Based on all-tenure household projections Multiplied by private sector ratio Projected ratio based on extrapolation of past values (2) Local Housing Strategy – Social rented housing Based on trends in new lettings and letting terminations New lettings dependent on all-tenure household projections by household type

3. Structure Plan Method - based on all-tenure household projection

4. Cohort Component Method

5. Data Requirements (1) Fertility Rates Mortality Rates -Males

6. Data Requirements (2a) In-outflow rates Private sector In-outflow rates Social rented sector

7. Data Requirements (2b) Net Flow Rates Males by Tenure

8. Data Requirements (3) Headship rates 2001 Projected headship rates 2015

9. Private Sector Comparison 2001-2015 Social Rented Sector Comparison 2001-2015 Model Output (1) – Population Age Pyramids

10. Model Output (2) - Households Households by Tenure and Type 2001 Households by Tenure and Type 2015

11. Comparison of Methods (1) Advantages of Cohort Component Method 1)Focus on population. Better understanding of factors behind tenure change: natural change population effect Net flow population effect Household formation effect 2)Age/household structure of population by tenure relevant for service planning 3)Useful for affordability analysis (young adults in private sector)

12. Comparison of Methods (2) Disadvantages of Cohort Component Method 1)Requires more detailed data Fertility and mortality rates by tenure are approximations Needs a Census for full validation 2)How stable are inflow/outflow rates by age/sex? Inflow/outflow concepts more difficult to interpret 3)Issues of consistency: sum projections by tenure = all tenure household projection

13. Comparison of Methods (3) Use of Cohort Component Method 1)Validation exercise using SLS, SHS, lettings and housing choice survey data 2)Used in parallel with ‘lettings’ model 3)Outcomes ‘controlled’ by results all-tenure household projection