Census and administrative data

1. Census and administrative data 1: Sources and methods

2. Census and administrative data • Lecture overview Objectives of lecture Social data entities Social data sources Questions Census and administrative data sources and processing Lecture summary

3. Objectives • Understand the variety of social entities in which we may be interested • Recognise the key data sources and their characteristics • Understand the processes by which these data sources are processed to create data outputs

4. Social data entities • What is the elemental information unit in which we are interested? • Neighbourhood (definitional issues) • Dwelling unit • Household • Person • Event (e.g. birth, death, hospital admission, etc.)

5. High Ease of access High Attributedetail Surveys Admin records Censuses Low Low Low High Level of aggregation

6. Administrative records • Population registers (esp. Scandinavia) • Registers maintained for the purposes of delivering a service • Driven by specific organisational needs • Few attribute details unless maintained as statistical register, but timely • Aggregated for output, but not at source

7. Population censuses • Aggregate data but available for small areas • High coverage rates but limitations of census questions (health, income, etc.) • Cross-tabulated to full range of socioeconomic characteristics • Infrequent (decennial) • Multiple data outputs

8. Social survey data • Even largest surveys cover only small proportion of population • Sampling error and small number problems • Advantage of timeliness • Geographical coverage difficulties • Potentially high levels of attribute detail and cross-tabulation possible

9. Introductory questions… What do we mean by ‘administrative’ data? How do the census questionnaire responses become data? Are the data reliable anyway?

10. Administrative sources • Population register (Netherlands, Denmark, etc.) • National health service register (NHSCR) • Electoral register • Council tax register • Hospital episodes system (HES) • Inland revenue database • Customer databases (loyalty cards, etc.)

11. LA register extract UPRN RV TYPE ADDRESS FIELDS N’hood (3) Street (4) Num (4)

12. Neighbourhood Statistics • Government departments contributing datasets derived from administrative records • Aggregating initially to 1998 wards, soon to be super output areas (SOAs) • Varying levels of SOA reflect sensitivity of different administrative datasets

13. NeSS

14. Neighbourhood Statistics

15. The 2001 census process… • Address pre-listing • Enumeration • Census 29 April 2001 • Collection of forms • Scanning of forms and creation of database • Census Coverage Survey • One Number Census processing • Output creation

16. Address listing

17. Enumerator’s map

18. Census field force Source: CHCC Unit 4 Source: ons.gov.uk

19. Collection and OCR • Post-back of majority of forms • Enumerators concentrate on forms not returned • OCR at single processing centre • Creation of database for checking and correction by census organisations Source: ons.gov.uk

20. Census Coverage Survey • Recognition of inevitable undercount • Coverage survey of 300,000 households 4-8 weeks after census • Intensive enumeration with no address pre-listing • Stratified sample of postcodes – by LAD and hard-to-count index

21. One Number Census • Dual system estimator: attempts to match census and CCS responses • Assess probabilities of being • Imputation of missing households and missing individuals within households • Modification of census database to produce ‘one number’ outputs • Cross-check against admin sources

22. Assignment 4 • Work through CHCC unit 1 ‘A quick introduction to the census’ and unit 4 ‘Census 2001: the enumeration process’ • Use NeSS to locate information about your chosen neighbourhood and retrieve attributes that particularly characterise that area

23. Lecture summary • Objects of interest • Administrative, census and survey sources • Admin and censuses for neighbourhoods • Administrative sources • Development of NeSS • Census data processing