About the Survey

The SSM survey series

The Social Stratification and Social Mobility (SSM) survey has been conducted every ten years since 1955 by research groups of Japanese sociologists. Its core questions—respondents’ occupational histories, educational attainment, and parents’ occupations and education—have been asked in a comparable form across waves, which makes the series a central resource for the study of inequality and mobility in Japan. SSM2025 is the eighth wave.

SSM2025 design

• Population: residents of Japan aged 20–79
• Sampling: stratified two-stage random sampling (650 sampling points) from the Basic Resident Registers
• Modes: face-to-face interviews combined with a self-administered (drop-off) questionnaire, with a self-administered mail follow-up
• Main content: current and first occupation, full occupational history, education, parents’ and spouse’s occupations and education, family formation, income, and social attitudes

The SSM2025 project also includes a survey of young adults, a regional survey, a survey of foreign residents, and a follow-up survey of respondents (autumn 2026).

Research organization

• Survey design: The 2025 SSM Survey Research Group
• Principal investigators: Sho Fujihara and Kikuko Nagayoshi (Institute of Social Science, The University of Tokyo)
• Funding: JSPS Grant-in-Aid for Specially Promoted Research (JP23H05402)

Data access

The SSM2025 data are currently being cleaned and coded, and are available only to members of the research group. Plans for public release will be announced on this site.

Acknowledging the data

Publications using SSM2025 data should state that the data come from the 2025 Social Stratification and Social Mobility Survey and that the survey was supported by JSPS KAKENHI Grant Number JP23H05402.

Contact

For information for survey respondents, see ssm2025.jp (in Japanese).