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Census and administrative data sources

3: Integration and future development

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Census and administrative data

• Lecture overviewObjectives of lecture

Introductory questions

Census challenges

Census data creation from individual records

Comparison with administrative sources

International comparisons

Future directions

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Objectives

• To understand why censuses are becoming less effective

• To consider alternative options for large scale social data collection

• To explore likely routes from the present situation to the next round of censuses

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Introductory questions…

Do we still need a census?

Is a census viable as a means of collecting social data?

Can’t we just use administrative records?

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Census challenges

• Declining response rates/difficulty of enumeration

• Rising demand for more up to date information

• Potential of extracting relevant data from administrative sources

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Data from census

• Reflections on class responses: data collection issues

• Coverage– Who was omitted?

• Accuracy– Who answered some questions incorrectly?

(intentional or unintentional)

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Extract of person data

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Imputation

• Validation of OCR records– Missing or impossible values

• One Number Census methodology– Missing individuals– Missing households

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Aggregation issues

• Table specification prior to data collection

• Application of disclosure control methodology– Table level: threshold populations (40

households, 100 persons)– Small cell adjustment (rounding to 0 or 3)– Record swapping

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Table framework

Total Male Female

:

18-19

20-24

25-29

30-34

35-39

Total

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‘Unsafe’ cells

Total Male Female

:

18-19 0 0 0

20-24 29 15 14

25-29 1 1 0

30-34 0 0 0

35-39 1 1 0

Total 31 17 14

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Record swapping

Total Male Female

:

18-19 0 0 0

20-24 28 14 14

25-29 2 2 0

30-34 0 0 0

35-39 1 1 0

Total 31 17 14

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Small cell rounding

Total Male Female

:

18-19 0 0 0

20-24 28 14 14

25-29 3 3 0

30-34 3 0 3

35-39 0 0 0

Total 34 17 17

Hard to code variables!

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NS-SeC

• National Statistics – socioeconomic classification

• Replaces former social class and SEG• Use for Census and all official surveys• Occupation-based• Based on occupation and employment

status

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NS-SeC: sample subdivisionsSourc

e:

ww

w.n

ati

onal.st

ati

stic

s.gov

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NS-SeC

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Interaction variables

Now 1 Year ago

SO16 0TG SO16 0TG

SO17 2FE SO14 2FE

SO17 2GT SO16 3SH

SO17 1NY

CR2 0AS SO16 7AB

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The rise of administrative data

• Can provide microdata from routinely updated administrative sources

• Can take snapshots and produce more frequent estimates than census

• BUT no comprehensive administrative population register

• Current barriers to data linkage without explicit consent of data subjects

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Census Ireland, South Africa

EDs for collection and output

Census, NeSS UK Postcode, OA/SOAs; aspiration to statistical population register

Short census, community survey

USA TIGER, blocks, communities

Rolling census France Neighbourhood data, commune coverage 1/5 or 1 in 5

No census, annual statistics

Sweden, Netherlands

Integrated registers, geographical flexibility

International comparisons

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France: rolling census

• Small communes (<10,000) once every five years

• Large communes sampled 1/5 per year, to achieve full coverage over five years

• No conventional complete enumeration

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USA: short form and ACS

• Abandon long form census (approx 1/6 sample in 2000 census)

• Retain short form census for 2010• American Community Survey,

continuously administered, covering 2.5% addresses per year, already started

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Netherlands: administrative census

• Statistical population register• Person ID and address provide

links to administrative records• 2001 ‘census’ data constructed by

snapshot matching of administrative registers

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Plans for UK 2011 Census

• Methodology essentially as in 2001 • Focus enumeration effort on those

areas hardest to count: greater variety of enumeration approaches

• Post-out and post-back of census forms

• Electronic form tracking system

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An integrated population statistics system?

• ONS consultation document autumn 2003

• 2011 census• Integrated social survey system• Statistical population register• Needs address register• Would require new legislation

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Lecture summary

• International challenges to census• Consideration of census data

creation• Retreat from census-taking• Rise of administrative data sources