The Scottish Government

Using Administrative Data in the Housing Supply Indicator

Claire Boag, Communities Analytical Services

Outline

• Who we are

• Pros and cons of administrative data

• NI 32 – Increase the rate of new house building. What does that actually mean?

• New build components

• Conversions

• Refurbishments

• Things to consider

Housing Statistics branch• Collect, analyse and disseminate housing data

• 20 administrative returns from local authorities:– Local authority housing management

– Changes to stock levels

– Right to buy sales

– New house building

• Also have access to administrative data collected by others:– Housing Benefit / Market Evidence

– Housing Association new build

– Landlord Registration

Advantages of administrative data• Low costs of obtaining data from an existing source.

• Faster and more frequent analysis may be possible.– In particular, the time between an event occurring and being

recorded– Eg - most housing stats data available immediately (exceptions

include private new build)– frequency – eg. quarterly figures for local authorities could be

difficult to achieve with a survey without huge expense

• Sometimes more detailed figures are available – Eg - for geographical areas where data has geographic

referencing

• No statistical sampling errors or non-response bias.

• Doesn’t rely on memory of respondent.

Disadvantages of administrative data• Effort may be needed to make administrative sources useable for statistical

purposes.Eg – estimating missing values, getting rid of redundant data, linking to other data sources

• Lack of independence – not controlled by statisticians.

• Definitions and classifications may often not be ideal for statistical purposes. Eg - data on housing association starts is actually based on approvals.

• Coverage of the data may not be complete and it may be difficult to make comparisons with other statistics.

Eg – landlord registration databaseEg – HB claimants from RRS v DWP

• Changes in provider data systems may cause discontinuities. Eg – housing list cleaning or system improvements

• There may be some danger of interruption to the supply of data.Eg - staff turnover in LAsEg – IT problems

• There may be constraints on the use of dataEg – Market Evidence Database

Housing supply indicator• Data on housing supply informs National Indicator 32

(Increase the rate of new house building), and comprises the following elements:

– new house building: houses completed by or for housing associations, local authorities or private developers for below market rent or low cost home ownership; houses completed for market sale by private developers.

– refurbishment: houses acquired by housing associations and refurbished either for rent or low cost home ownership. Refurbishment of private dwellings funded wholly or partly through the Affordable Housing Investment Programme.

– conversion: new dwellings created by conversion from non-housing to housing use.

Housing supply indicator

Terminology issues• Increase the rate of new house building

– Uses absolute numbers not rates– Includes new housing provided through other means

Supply of new housing in Scotland: 1996-97 to 2007-08

0

5,000

10,000

15,000

20,000

25,000

30,000

1996-97 1997-98 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08

ne

w d

we

llin

gs

Local authoritynew build

Conversion

Refurbishment

Housingassociation newbuild

Private new build

Private new build data

• Data provided on a quarterly basis by local authorities via the NB2 return.

• Can be based on different data/methods in each LA though each should be consistent over time.

• No marked seasonality but data for individual quarters is volatile therefore quarterly change unreliable

New private house completions in Scotland

-

1,000

2,000

3,000

4,000

5,000

6,000

7,000

Co

mp

leti

on

s

Local authority new build data

• Data provided on a quarterly basis by local authorities via the NB1 return.

• Council house building limited in recent years, therefore numbers small and data volatile

• Errors fairly unlikely since numbers low

New council house completions in Scotland

-

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

Qu

arte

rly

Co

mp

leti

on

s

Housing association new build data

• Data provided on a quarterly basis by HID colleagues from the AHIP database

• Data provided by those involved with managing the developments therefore quality higher than private new build.

• Very volatile

New housing association completions in Scotland

-

500

1,000

1,500

2,000

2,500

3,000

Qu

arte

rly

Co

mp

leti

on

s

Annual new build

• Annual new build data much less volatile – change more clearly shown• Issues - Need to watch out for duplication across sectors

– LA new build with AHIP funding

– Purchase of private new build by LA for social rent

New house building in Scotland

-

5,000

10,000

15,000

20,000

25,000

30,00019

80-8

1

1981

-82

1982

-83

1983

-84

1984

-85

1985

-86

1986

-87

1987

-88

1988

-89

1989

-90

1990

-91

1991

-92

1992

-93

1993

-94

1994

-95

1995

-96

1996

-97

1997

-98

1998

-99

1999

-00

2000

-01

2001

-02

2002

-03

2003

-04

2004

-05

2005

-06

2006

-07

2007

-08

Co

mp

leti

on

s

Private sector Housing association Public authority All completions

ConversionsNew Dwellings Provided by Conversion

-

200

400

600

800

1,000

1,200

1,400

1,600

1,800

con

vers

ion

s to

ho

usi

ng

use

• Collected from local authorities through annual return

Refurbishments

• This is proxy data – we only have information on housing association refurbishments and private refurbishments receiving public subsidy.

• All other private refurbishments (resulting in addition to housing supply) are excluded

Refurbishments for social rent and private refurbishments receiving public subsidy

0

200

400

600

800

1,000

1,200

1,400

1,600

1996

-97

1997

-98

1998

-99

1999

-00

2000

-01

2001

-02

2002

-03

2003

-04

2004

-05

2005

-06

2006

-07

2007

-08

Co

mp

leti

on

s

Things to consider (1)How and why was the data collected?• Private and local authority new build

– Paper based returns, produced purely for the SG. Data tends not to be heavily used within the councils (with a few exceptions).

– Labour intensive, burdensome return – Based on a combination of completion certificates, site visits and

council tax assessors data– Smaller, more urban local authorities are more likely to use site

visits, large rural authorities need to rely on completion certificates– There is anecdotal evidence that there are issues with completion

certificates in some councils, eg: self-builders have no incentive to apply for a certificate. Often long delays between ‘effective’ completion and legal completion.

Things to consider (2)How and why was the data collected?• Housing association new build and refurbishments

– Information collected by SG Housing Investment Division to monitor Affordable Housing Investment Programme.

– Data extracted from live database, and HID carry out quality assurance checks before passing it on.

– Delays in the recording of completions mean that the data is subject to annual revisions each March, therefore quarterly or calendar year monitoring inappropriate.

• Conversions– Information on conversions are provided by local authorities on the

annual Stock4 return. – Data is provided in summary form, therefore there is little scope for

us to check the accuracy, other than to compare with other LAs and over time

– Difficulty collecting information from local authorities

Things to consider (3)Is there a consistent time series of estimates?• Private and local authority new build

– Information has been collected in its current form since 1986.– Issues with data for Highland – new source used, but revisions

made back to 2000 so no issues with consistency in recent years.– If a local authority changes the way it collects or records the

information, we will only know if they tell us.

• Housing association new build and refurbishments– provided since 1992– Changes afoot with HA starts – we will need to consider creating

consistent back series

• Conversions– Consistent at least since 2001. Prior to that was collected as part

of new build data. No obvious inconsistencies

Summary

• Know how the data is collected – More scope for error with paper based collection– Data that is difficult to collect will be more error prone

• Know why the data is collected and how it’s used by the provider– The more it’s used by the data provider, the more accurate it should be

• Understand the nature of volatility in the data– Is it a real change or a data artefact?– Investigate unexpected peaks and troughs

• Know whether there are definitional or system changes that would cause a discontinuity in a time series

Contacts

Emailhousingstatistics@scotland.gsi.gov.uk, or

Telephone: 0131 244 7234

Fax: 0131 244 0446

Post:Communities Analytical Services (Housing Statistics) Area 1-F Dockside Scottish Government Victoria Quay Edinburgh EH6 6QQ