Household Analysis Review Group 12 April 2011 Incorporating Survey - - PowerPoint PPT Presentation

Household Analysis Review Group 12 April 2011

NRS: Household Estimates and Projections

Incorporating Survey Data in Household Projections

Background

Household Projections are calculated using

• Most recent population projections
• With updated CE data
• The most recent household estimates

but

• Estimates for the number of households of

each type are projected forward from the 1991 and 2001 Censuses

2008-based Household Projections

2008 Household Types

All Households 2,331,250

1 person households 2 person households 3 person households

1 adult male 1 adult female

840,790 1 adult, 1 child 2 adults 1 adult, 2+ children 3+ adults 2+ adults, 1+ children 795,890 694,570

Projected numbers of household types, Scotland

200,000 400,000 600,000 800,000 1,000,000

1 adult male 1 adult female 2 adults 1 adult, 1 child 1 adult, 2+ children 2+ adult, 1+ children 3+ adults, no children

2008 2033

+56% +44% +23% +56% +33%

• 27%
• 27%

Survey Data

The Scottish Household Survey (SHS)

• Covers approximately 15,000 households per year

Labour Force (LFS) and Annual Population Surveys (APS)

• LF survey covered approximately 8,000 households
• In 2003 the LFS was boosted to 23,000 households

and is now renamed the APS

Comparing Survey proportions and projected Census proportions

SCOTLAND - 2+ adults, 1+ children

Projections adj SHS LFS APS SHS

14% 16% 18% 20% 22% 24% 26% 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

Projections adj SHS LFS APS Census SHS Census points

SCOTLAND - 1 adult: female

Projections adj SHS LFS APS SHS

16% 18% 20% 22% 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

Projections adj SHS LFS APS Census SHS Census points

Comparing Survey proportions and projected Census proportions

Combining Survey and Projected data

• SHS data was used as it can be calibrated to

2001 proportions

• To reflect uncertainty over accuracy of survey data

a maximum weight of 50% was decided on, linked to the time since the last census.

• To overcome some of the variability in the survey

data a 3 year smoothed average was used.

1 adult: female - 3 year smoothed SHS data

18% 19% 20% 21% 22% 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

3 year smoothed adj SHS adj projections 02-04 adj projections 04-06 adj projections 06-08 Projections

Projected proportions adjusted using 3 year smoothed SHS data

Smoothed average for 2006, 2007, 2008 Adjusted projection

SCOTLAND -

Diagram of Processing

Calculate household projection Control LA figures to Scottish Totals Calculate private population from CE data and the population projection Constrain to GROS household estimates Project headship rates from 1991 and 2001 census Constrain to Scottish SHS household type proportions Adjust SHS household proportions to 2001 Census proportions Carry out minimum adult and minimum child adjustments Sum Authorities to get Scotland figures Reformat and

• utput results

Comparing Scotland Results

Household size Household type unadjusted shs adjusted unadjusted shs adjusted 1 adult male 370,160 367,720 578,060 573,760 1 adult female 470,630 465,020 675,940 667,510 2 adults 701,910 701,310 865,670 865,300 1 adult, 1 child 93,980 92,860 146,410 144,360 1 adult, 2+ children 68,900 66,350 91,450 87,880 2+ adult 1+ children 433,420 437,980 314,970 318,060 3+ person all adult 192,250 200,010 140,000 145,530 2,331,250 2,331,250 2,812,500 2,802,400 3+ person households All households 2008 2033 One person households Two person households

Scotland, Household types, percentage difference from unadjusted projections to SHS adjusted projections

• 5%
• 4%
• 3%
• 2%
• 1%

0% 1% 2% 3% 4% 5% 1 adult male 1 adult female 2 adults 1 adult, 1 child 1 adult, 2+ children 2+ adult, 1+ children 3+ adults, no children

Household type Percentage Difference 2008 2033

• 0.6%
• 0.5%
• 0.4%
• 0.3%
• 0.2%
• 0.1%

0.0%

Aberdeen City Aberdeenshire Angus Argyll & Bute Clackmannanshire Dumfries & Galloway Dundee City East Ayrshire East Dunbartonshire East Lothian East Renfrewshire Edinburgh, City of Eilean Siar Falkirk Fife Glasgow City Highland Inverclyde Midlothian Moray North Ayrshire North Lanarkshire Orkney Islands Perth & Kinross Renfrewshire Scottish Borders Shetland Islands South Ayrshire South Lanarkshire Stirling West Dunbartonshire West Lothian

Percentage Difference

Local Authority, Household types, percentage difference from unadjusted projections to SHS adjusted projections in 2033

HARG members are asked to comment on the analysis presented here and consider whether it is be appropriate to make adjustments to future household projections using survey data.