Transcript DWP's families with Children Model: From ONS projections to DWP policy.

Families with Children
Projection Model:
From ONS Projections to DWP Policy
An overview
9th September 2009
Introduction
ONS produce:
- National Population Projections
- Marital/cohabiting Population Projections
- Parity Projections
DWP require projected numbers of lone parents and
couples with dependent children for:
- FRS grossing factors
- Income Support for Lone Parents benefit expenditure
forecasting
- Child Maintenance eligible population
2
Summary
Stock-based model providing numbers of lone
parents and couples with dependent children,
split by:
•Male/Female
•Single year of age: 16-64
•Marital/partnership status
GB-based
Projected from 2008/09 – 2074/75
3
Age-specific Proportions
LFS spring data from 1997 to the latest year
Nine groups of marital status and family types derived:
4
Single-living alone
Single-cohabiting
Married/separated-living alone
Married-cohabiting
Separated-cohabiting
Widowed-living alone
Widowed-cohabiting
Divorced-living alone
Divorced-cohabiting
Population Projections by marital/partnership status
ONS marital/cohabiting projections (2003-based)
- Updated for actual numbers to 2005
- Proportions from 2003 applied to 2006-based National Population
Projections
Legal Marital Status
Never Married
Married
Widowed
Divorced
Cohabiting Status
Never Married
Separated
Widowed
Divorced
Need consistent nine groups by marital status and
family type:
Married/separated living alone
Married living with spouse
5
Population Projections by marital/partnership status
6
Fertility Adjustment Factor
Parity estimates produced by ONS.
-
For England and Wales, but provide proxy projections for the
proportions of females with dependent children for GB for each
female cohort.
Fertility Adjustment Factor
-
-
Attempt to mimic the delay in child birth commonly observed
across cohorts in recent years and apply this to the projections.
Male fertility adjustment factor assumed to be a 3 years older
than for females.
Apply ‘best fit’ distribution for dependents under a certain age
ONS Parity – age of oldest child vs. LFS – age of youngest child
7
Fertility Adjustment Factor
0.90
Comparison of LFS proportions of women with youngest child aged
under 19 against ONS proportions of women with oldest children
aged under various ages,
pooled 2004-2008 data
0.70
0.60
0.50
0.40
0.30
0.20
0.10
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
0.00
16
Proportions of females with
dependent children
0.80
Age of mother
ONS - Children aged under 25
ONS - Children aged under 19
8
ONS - Children aged under 23
LFS - Children aged under 19
ONS - Children aged under 21
Summary of calculation
9
Summary of calculation
RAW PROJECTIONS
Population with Dependent
Children Projections:
LFS proportions split by
marital status
x
ONS Female Marital
Population Projections
x
ONS Female
Fertility Adjustments
Factors
‘BEST’ ESTIMATE TOTAL
Population with Dependent
Children Projections:
LFS Total Females
proportions
x
ONS Female Total
Population Projections
x
ONS Female
Fertility Adjustments
Factors
10
DIFFERENCE
Total population projections minus
Total sum of split by marital status
REALLOCATION PROJECTIONS
Apply difference proportionately to
‘single – living alone’ and ‘single – cohabiting’
DIFFERENCE
Reallocated Total Numbers (actual years)
minus Total LFS Number (actual years)
ALIGNED PROJECTIONS
Apply pooled alignment factor to all categories
Users
Family Resources Survey (FRS) Team
- Grossing factor for lone parents
Poverty Team
- Numbers of lone parents
Forecasters of Income Support for Lone Parents
- Look at those with dependents aged under 19, 16, 12 and 7
Child Maintenance Support/Strategy Teams
- Family formation/future workload
Model Development Teams
- Provides source of inputs for family structure/validation tool
11
Future Work
Short-term
Update with:
Spring 2009 LFS data
2006-based Marital/cohabiting status Population Projections
2008-based National Population Projections
Long-term
Convert the FWC model to a microsimulation model
12