1. Statistics Netherlands Division Social and Spatial Statistics
Censuses in the Netherlands and the availability of census micro datasets
Eric Schulte Nordholt
Statistics Netherlands
Division Social and Spatial Statistics
Presentation in Paris

2. Contents History of the Dutch Census
Introduction Virtual Census of 2001
Combining data sources: micro-linkage
Combining sources: micro-integration
Preliminary work
Harmonisation
More information about the Dutch Censuses
of 1960, 1971 and 2001
Conclusions

3. History of the Dutch Census
TRADITIONAL CENSUS
Ministry of Home Affairs:
1829, 1839, 1849, 1859, 1869, 1879 and 1889
Statistics Netherlands:
1899, 1909, 1920, 1930, 1947, 1960 and 1971
Unwillingness (non-response) and reduction expenses  no more Traditional Censuses
ALTERNATIVE: VIRTUAL CENSUS
1981 and 1991: Population Register and surveys
development 90’s: more registers →
2001: integrated set of registers and surveys, SSD

4. Introduction Virtual Census of 2001
Why a Census?
Statistical information for research and policy purposes
What kind of information?
Size of (sub)population(s)
Demographic and socio-economic characteristics, at national and regional level
Gentlemen’s agreement
Eurostat: co-ordinator of EU, accession and EFTA
countries in the 2001 Census Round
Census Table Programme, every 10 years

5. Combining sources: micro-linkage
Linkage key: Registers Social security and Fiscal number (SoFi), unique Surveys Sex, date of birth, address (postal code and house number)
Linkage key replaced by RIN-person
Linkage strategy Optimizing number of matches Minimizing number of mismatches and missed matches

6. Combining sources: micro-integration
Collecting data from several sources  more comprehensive and coherent information on aspects of person’s life
Compare sources coverage conflicting information (reliability of sources)
Integration rules
- checks adjustments imputations
Optimal use of information  quality improves
Example: job period vs. benefit period

7. Preliminary work
Census Programme definitions: not always clear and unambiguous, e.g. economic activity
Priority rules
(characteristics of) main job (highest wage)
employee or employer
job or (partially) unemployed
job or attending education
job or retired
engaged in family duties or retired
age restrictions
One percent samples for all three years
Weighting to population totals
Protecting according to rules for
public use files

8. Harmonisation (1) For 1960 and 1971 the same variables as for 2001
if not available: constructed based on existing variables in Census data
Variables not internationally harmonised (e.g. sex, age, marital status, household position, country of birth, economic status, household size and country of citizenship)
same classification and priority rules as for 2001

9. Harmonisation (2) Household size and country of citizenship:
missing for 1960
Religious denomination:
only for 1960 and 1971
Place of residence one year prior to the census:
only for 2001
International classifications
Branch of current economic activity: ISIC / NACE
Occupation: ISCO-COM
Level of educational attainment: ISCED

10. Harmonisation (3)
1960
1971
2001
Sex X
Age
Country of citizenship
Marital status
Household position
Religious denomination
Country of birth
Household size
Place of residence one year prior to the census
Economic status
Level of educational attainment
Occupation
Branch of current economic activity

11. More information about the Dutch Censuses of 1960, 1971 and 2001
1960:
1971:
2001 tables:
2001 book:

12. Conclusions The Dutch Virtual Census of 2001 was successful Pro’s:
relatively cheap (cost per inhabitant)
quick
Con’s:
publication of small subpopulations sometimes difficult or even impossible because of limited information
Micro datasets for three years (1960, 1971 and 2001) available for research!