GEOG3025

Census and administrative data

1: Sources and methods

GEOG3025

Census and administrative data

• Lecture overviewObjectives of lecture

Social data entities

Social data sources

Questions

Census and administrative data sources and processing

Lecture summary

GEOG3025

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

GEOG3025

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.)

GEOG3025

Attribute detail

Ease of access

Level of aggregation

Censuses

Surveys

Admin records

Low

Low

Low

High

High

High

GEOG3025

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

GEOG3025

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

GEOG3025

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

GEOG3025

Introductory questions…

What do we mean by ‘administrative’ data?

How do the census questionnaire responses become data?

Are the data

reliable anyway?

GEOG3025

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.)

GEOG3025

LA register extractUPRN RV TYPE ADDRESS FIELDS

N’hood (3)

Street (4)

Num (4)

GEOG3025

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

GEOG3025

NeSS

GEOG3025

Neighbourhood Statistics

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

GEOG3025

Address listing

Enumerator’s map

Census field force

Sourc

e:

CH

CC

Unit

4

Sourc

e:

ons.

gov.u

k

GEOG3025

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

Sourc

e:

ons.

gov.u

k

GEOG3025

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

GEOG3025

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

GEOG3025

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

GEOG3025

Lecture summary

• Objects of interest• Administrative, census and survey

sources– Admin and censuses for neighbourhoods

• Administrative sources– Development of NeSS

• Census data processing