1. Comment on “Making Accessible Longitudinal Administrative Data Worldwide”
Wataru NAKAZAWA
Osaka University, Japan
WERA Invited Education University of Hong Kong
December 1st, 2017

2. Background (1) The spread of “evidence-based policy”
Causal inferences in social science become more important.
Longitudinal data can be regarded as a prerequisite for causal inference (Lieberson 1985).
Quasi-experimental (natural experimental) designs or statistical analysis to estimate the “net” treatment effect are introduced to social science(Gangl 2010; Morgan and Winship 2014).
DID (difference-in-differences) estimation, instrumental variable methods, propensity score matching, regression discontinuity design, fixed effect models in econometrics, etc.

3. Background (2)
International comparative data are available to researchers.
PISA, TIMSS, TALIS, PIACC, etc.
It is possible to combine national level data with these survey data, and to employ multilevel models.
However, these data are cross-sectional.
There is a limit to specifying the causal relationship with these data.

4. Japanese government position
While there are well-designed longitudinal surveys in Western countries, Korea, and Taiwan, large longitudinal survey was not conducted in Japanese schools.
The Ministry of Education did not track the development of children, and does NOT have any data.
Originally, the Japanese government is not positive to open the administrative data due to shortage of working staff and budgets, a disregard for data analysis, and legal restrictions.

5. Japanese social scientists position
Social scientists demand the government to open the administrative data.
However, some scholars obtained grants from the Japan Society for the Promotion of Science (JSPS), and started conducting longitudinal surveys for themselves.

6. Current problems regarding longitudinal surveys in Japan
Japanese social scientists usually share these data and codebooks in Japanese version.
If they wish to share these data with the international data system, they have to prepare the data and the codebooks in English.
However, most of them do not feel the need to share English version of data and codebooks, because they have no urgent incentives to prepare the English version (There is still relatively large academic job market of Japanese, and they usually write papers and books in Japanese, except for the frontier of economics).
They usually have no budget allocation to pay costs and assign human resources to prepare the English version.
I would like to know more about the data construction and preservation systems in other non-English speaking countries.

7. Guideline
I think that the content is similar to the system of Social Science Japan Data Archive (SSJDA) and other Data Archive (ICPSR, UKDA, GESIS, etc.), and I did not find anything missing and problems.
SSJDA ( )
Data sharing through Data Archive becomes common among Japanese scholars.
Some Japanese scholars may be interested in this longitudinal administrative data system.
Probably, they feel concerned about costs to join the international network of longitudinal data.

8. Administrative data
There are many kinds of administrative data in Japan, but only accessible to aggregate data through the website of Statistical Bureau.
Difficult to keep up with long-term change because of changes in the definition of category or classification used in aggregate datasets.
If we can use the time-series
format of administrative data
found in Education at a
Glance published by the OECD,
it must be helpful for many
scholars and researchers.

9. Diffusion of longitudinal data analysis
Workshops and seminars are useful.
Longitudinal survey designs vary among countries.
Data handling of longitudinal data is more likely to be complex.
Users have to understand the local social (institutional) context for correct explanation.
Difficult to read all of manuals or codebooks.
In principle, the expansion of international network of longitudinal data usage should be welcomed!