Household Projections for Wales

Tony Whiffen

Presentation Outline

• Background• Broad Methodology - Wales• Wales Results / Issues• Future Plans

Background

• 2003-based household projections for Wales (2006)– only available at regional level

– Last set under DCLG / Anglia Ruskin contract

• Opportunity to develop own methodology 2007-08– Population and Households

– Local Authority level projections

– Not constrained Wales NPP ≠ ∑ 22 Local Authority Projections

Background

• Membership method chosen 2008• 2006-based household projections for

Wales published June 2009• 2008-based set September 2010• Variant projections• Also National Park projections• Using HOUSEGROUP WALES

(forerunner to Derived Forecasts)

Variant Projections

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

Household Estimates

• Household Estimates 2010 (Feb 2011)

• Based on ONS population estimates not Council Tax estimates

• Effectively ‘projected estimates’– Populations – estimated– Household membership rates - projected

Broad Methodology

• Use Membership Rates

• Household types based on size and presence of children

• Census data used to project membership rates– APS considered but rejected

• 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

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

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)

Membership Rates – Range

0

0.2

0.4

0.6

0.8

1

2008 2013 2018 2023 2028 2033Hou

seho

ld M

embe

rshi

p ra

te f

or a

ge

and

sex

grou

p

Rate 1

Rate 2

Membership Rates: Largest increases/decreases

0

0.2

0.4

0.6

0.8

1

2008 2013 2018 2023 2028 2033Hou

seho

ld M

embe

rshi

p ra

te f

or a

ge

and

sex

grou

p

Rate 3

Rate 4

Household projections by local authority, Wales, 2008-2033 (a) Thousands and per cent

2008 2013 2018 2023 2028 2033

Percentage change,

2008 to 2033

Wales(b) 1,297.3 1,366.4 1,440.3 1,509.2 1,568.5 1,620.3 25

Isle of Anglesey 30.6 32.0 33.4 34.5 35.3 35.8 17

Gwynedd 51.9 53.8 55.7 57.5 59.0 60.3 16

Conwy 50.7 52.8 55.0 57.0 58.7 59.9 18

Denbighshire 43.1 45.8 48.5 51.2 53.5 55.3 28

Flintshire 64.1 67.1 69.9 72.2 73.8 74.6 16

Wrexham 57.2 60.7 64.1 67.4 70.2 72.7 27

Powys 59.0 63.0 66.7 70.0 72.7 74.6 26

Ceredigion 32.8 34.3 35.9 37.4 38.6 39.5 20

Pembrokeshire 52.1 55.2 58.1 60.6 62.7 64.4 24

Carmarthenshire 80.3 86.2 92.0 97.5 102.5 106.8 33

Swansea 100.5 106.5 112.7 118.8 124.4 129.9 29

Neath Port Talbot 62.1 65.8 69.3 72.5 75.4 77.9 26

Bridgend 58.2 62.0 65.7 69.2 72.2 74.7 28

The Vale of Glamorgan 52.8 56.2 59.6 62.7 65.4 67.7 28

Cardiff 136.7 149.7 164.2 178.8 192.8 207.5 52

Rhondda Cynon Taf 99.1 103.0 106.9 110.4 113.1 115.4 16

Merthyr Tydfil 23.9 24.9 25.8 26.5 27.0 27.5 15

Caerphilly 74.0 77.8 81.4 84.4 86.7 88.6 20

Blaenau Gwent 30.7 32.1 33.5 34.6 35.5 36.2 18

Torfaen 38.8 39.8 40.7 41.3 41.6 41.6 7

Monmouthshire 38.1 40.2 42.2 44.0 45.2 45.9 20

Newport 59.6 62.0 64.7 67.0 68.9 70.7 19

(a) Based on the 2008-based Local Authority Population Projections

(b) Based on the 2008-based National Population Projection

Projected Households, Wales

1,000

1,100

1,200

1,300

1,400

1,500

1,600

1,700

2006 2011 2016 2021 2026 2031

Hou

seho

lds

(Tho

usan

ds)

2003-based

2006-based

2008-based

Projected Total Population, Wales

2,700

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

2008-basedprojection

2010-basedprojection

Source: Government Actuary’s Department / ONS

Net migration assumptions, 2006-based and 2008-basedLA Population Projections for Wales

2006-based 2008-based Difference

% Difference in Projected Households

2031

Isle of Anglesey +190 +210 +20 1%

Gwynedd +420 +250 -170 -5%

Conwy +940 +620 -320 -6%

Denbighshire +890 +640 -250 -4%

Flintshire +130 -110 -240 -3%

Wrexham +430 +440 +10 1%

Powys +1,190 +930 -260 -4%

Ceredigion +630 +410 -220 -7%

Pembrokeshire +850 +600 -250 -4%

Carmarthenshire +1,580 +1,400 -180 -1%

Swansea +900 +960 +60 2%

Neath Port Talbot +830 +460 -370 -6%

Bridgend +670 +610 -60 -1%

Vale of Glamorgan +820 +570 -250 -3%

Cardiff +630 +2,440 +1,810 15%

Rhondda Cynon Taf +300 +130 -170 -3%

Merthyr Tydfil -140 -40 +100 5%

Caerphilly +140 +50 -90 -1%

Blaenau Gwent +30 +30 +0 0%

Torfaen -40 -100 -60 -5%

Monmouthshire +620 +370 -250 -6%

Newport +220 -190 -410 -5%

Future Plans

• Look at Migration assumptions in LA Population Projections

• Assess projections vs 2011 Census results– Analysis of ‘actual’ vs ‘projected’ 2011 figures– Third point to project household trends from– New Assumption for Communal

Establishments population

Future Plans

• Shorter time lag between LA Population and Household Projections

• Membership rate variants ?

Further information

www.wales.gov.uk/statistics

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

Phone: 029 2082 1595