Household Projections for Wales

(2006-based)

Presentation Outline

• Background• Methodology• Wales Results• Household Estimates• HOUSEGROUP WALES

Background

• 2003-based household projections only available at regional level for Wales

• 2006-based local authority population projections for Wales published June 2008

• Opportunity to produce first ‘bottom up’ household projections for Wales

Initial Stages

• Literature review of methods in use

• Working Group set up early 2008 - WASHP

– Mainly local authority researchers from Wales

• User Consultation June 2008

Consultation Responses

• Regional geography not useful• Update projections every two years• Estimates and projections broken down by

household type• Household type defined by size and presence of

children• Variant projections needed• Make source data and model available

Broad Methodology

• Use Membership not Headship Rates

• Household types based on size and presence of children

• Census data used to project membership rates

• Outputs broken down by household type

The Membership Method

• Formula:

t

agtiagiagiMag

Fag

t

ti size

ycommpoph

*,16

,1

12

1

)(

where hi = total households in year it = household typeag = age and gender grouppopagi = population in age and gender group ag in year icommagi = communal establishment population in age and gender group ag in year iyagti = membership rate for age and gender group ag and household type t in year isizet = household size for type t

Household Population

• Total Population minus Communal Establishments Population

• Data on Communal Establishments from 2001 Census

• Number aged under 75, Proportion aged over 75 held constant

1 person 4 person (no children)

2 person (no children) 4 person (2+ adults, 1+ children)

2 person (1 adult, 1 child) 4 person (1 adult, 3 children)

3 person (no children) 5 + person (no children)

3 person (2 adults, 1 child) 5 + person (2+ adults, 1+ children)

3 person (1 adult, 2 children) 5 + person (1 adult, 4 + children)

Household Types

0-4 40-44

5-9 45-49

10-15 50-54

16-18 55-59

19-24 60-64

25-29 65-74

30-34 75-84

35-39 85+

Age Bands

Membership Rates• Data from 1991 and 2001 Censuses used as APS/LFS data not suitable• Two point exponential model used as a result:

ixi abky

ixi abky

where i = the yearyi = membership rate in year ik = 1 if y2001 ≥ y1991 0 if y2001 < y1991a = y1991 – kb = (y2001 – k)/(y1991 – k)xi = (i – 1991)/(2001 – 1991)

The Membership Method

• Formula:

t

agtiagiagiMag

Fag

t

ti size

ycommpoph

*,16

,1

12

1

)(

where hi = total households in year it = household typeag = age and gender grouppopagi = population in age and gender group ag in year icommagi = communal establishment population in age and gender group ag in year iyagti = membership rate for age and gender group ag and household type t in year isizet = household size for type t

National and Local Projections

• Method applied to national and LA population projections

• Results by LA not constrained to national ones

Variant Projections

• Produced using available variant population projections only– High: high fertility and low mortality – Low: low fertility and high mortality– Natural Change only / Zero Migration

• Variant membership rate assumptions not used for 2006-based set

Projected Households, Wales

1,0001,100

1,2001,300

1,4001,500

1,6001,700

1,800

2006 2011 2016 2021 2026 2031

Hou

seho

lds

(Tho

usan

ds)

2006-based

High Variant

Low Variant

2003-based

Projected Total Population, Wales

2,800

2,900

3,000

3,100

3,200

3,300

3,400

2006 2011 2016 2021 2026 2031

Tho

usan

ds

2006-basedprojection

2003-basedprojection

Source: Government Actuary’s Department

Projected Household by Type, Wales

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2006 2011 2016 2021 2026 2031

Hou

seho

lds

(Tho

usan

ds)

5 person

4 person

3 person

2 person

1 person

Average Household Size, Wales

0

0.5

1

1.5

2

2.5

2006 2011 2016 2021 2026 2031

Ave

rage

Siz

e (P

erso

ns)

HOUSEGROUP WALES

• Enable dissemination• New methodology• Based on

HOUSEGROUP / POPGROUP

• Uses desktop software (Excel)

• Copies available

Future Development

• Revisit APS/LFS data

• Improved Communal Establishment counts

• 2008-based Household Projections following revised MYE

• Other variants

Further informationNewsletters

Household estimates and projections pagewww.wales.gov.uk/statistics

Email: stats.housing@wales.gsi.gov.uk

Phone: 029 2082 5616