1. Item 2.2 Scientific Use Files for the Time Use Survey

2. Scientific Use Files (SUFs)
Confidential microdata made available for research purposes
Inside the research entity
Partial anonymisation
The research entity is responsible for output checking
Regulation 557/2013

3. Time use survey 1 HETUS: Harmonised European Time Use Survey
Collected once in 10 years: current proposal concerns 2010 data
Microdata available at Eurostat for 18 countries (voluntary)
In total 17 countries agreed in principle to produce SUFs

4. Time use survey 2
The value added is in the specific time use variables
These variables are neither identifying nor sensitive
The design differs over the countries, notably the number of diary days per respondent and the sample size
The sample size is relatively small compared to the Labour Force Survey and Statistics in Income and Living Conditions

5. Approach to the partial protection
Complete removal of some variables: exact date of diary, current education
Aggregation: age in 5-years age group, marital status, country of birth, country of citizenship
The survey does not have regional breakdowns

6. Analysis of the disclosure risk
Indirect identifiers: age, sex, marital status, country of birth, country of citizenship, life cycle
Analyse disclosure risk on the basis of four dimensional tables of the indirect identifiers
Analysis of four example countries, two with a relatively large sample (AT, DE) and two with the smallest sample (LU, NL)

7. Number of unique records after the proposed treatment
Austria
Germany
Luxembourg
The Netherlands
Number %
Table 1 25
0.3 28 19
0.9
Table 2 31
0.4 32 35
1.7 8
Table 3
138
107
5.1
Table 4 54
0.7 74
0.8 3
0.1
Table 5 55 41
0.5 5
0.2
Table 6 
165
2.0
1.2

8. Conclusions from the analysis
The number of unique records remains below 1% in most cases
Some unique records contain missing values on an indirect identifier
Perhaps some need of country specific solutions: e.g. Luxembourg for the education variable

9. Opinion of the Expert Group on Statistical Disclosure Control
9 out of 12 Members replied
All positive
Comments on the coherent aggregation of age
Request for additional analysis on economic activity and occupation
Identification of some mistakes and unclarity in the document
Some country specific situations

10. Conclusion
The WG is requested to agree to the general approach for the protection of SUFs for HETUS 2010
Under the condition that the document is updated on the basis of the comments of the Expert Group (notably a coherent aggregation of age)

11. Next steps
Eurostat will update the document and send it to both the Expert Group and the WG
If no further comments the method is approved
Eurostat will produce the SUFs
Add information on the identification risk including the requested tables for economic activity and occupation
Send to the specific MS with request to approve
This might lead to some country specific protection requests