1. SOEP and DOI Requirements and Challenges
Jan Goebel

2. Content
SOEP Overview
Problems
Conclusions

3. SOEP Overview
Socio-Economic Panel Study (SOEP) is a representative longitudinal study of private households in Germany
Annual survey since 1984 of about 10,000 households (around 20,000 persons)
Some of the many topics include household composition, occupational biographies, employment, earnings, health and indicators of subjective well-being

4. SOEP is an ongoing Survey
Common with all panel surveys
Each year we distribute an enhanced version with new and changed data
Question are changing, new topics, ... → We do a lot but not just replication!
Even changes for „archived data“, like a change in the coding scheme of ISCO

5. SOEP is not one dataset but a complex data structure
The SOEP currently (User DVD) consists of:
More than 320 data files
About Variables
Granulation to choose for citation?
Complete SOEP distribution of one year?
„Connected“ SOEP parts, e.g. Individual questionnaires, HH-questionnaires, generated datasets
Each data file
Each Variable (for each year or only once, longitudinal concept?)

6. „The SOEP” is available in different versions
European user: 100% Version (English, German, different formats for SAS/SPSS/Stata/ASCII)
Non-EU user: 95% Version (of cases)
International comparative research: Part of the CNEF (Cross National Equivalent File)
SOEP Geocodes (supplementary CD): Regional Planning Regions, Community types, etc.
Country codes, Community codes, zip codes, microm: only by remote execution or at the Research Data Center (RDC SOEP)
SOEP Pretests
SOEP Related Studies

7. SOEP can change during the period, because of updates
Updates of weighting schemes or even bug fixes (also possible for older waves)
Sometimes more than one update between distributions (cumulative updates?)
How can a user know what version she is using?
Message-Digest Algorithm (MD5)
Secure Hash Algorithm (SHA-2)
Universal Numeric Fingerprint (UNF)
Does rounding matter?
German/English Labels, different formats (SPSS, STATA, …)
Only update of a label bug?

8. Conclusions Nesting of DOI should be possible:
Print
DOI
SOEP example
SOEP DOI
Edited book
Survey
SOEP DVD
/soep.26
Article in book
Data file
SOEP dataset $PGEN
/soep.26.hgen
Table in article in book
Variable
SOEP dataset $pgen variable ihinc$$
/soep.26.hgen.ihinc
It should be possible for a user to identify the data, including version
 The metadata of a DOI should include a SHA for each data file and format, which must also be persistent, like SHA-2
Commitment about the persistence of the data provider
It is not enough to identify the data source to make an scientific empirical analysis reproducible, you normally need the syntax also

9. Thank you for your attention!