Self-Study and Pay in Japan: What Kind of Learning Mattered

What the research found

Takashi Sakamoto (2018) of the Recruit Works Institute used the Japanese Panel Study of Employment Dynamics (JPSED) to look at whether regular (full-time, permanent) employees did self-directed study, and how their annual income changed over the next two years. Self-study here means anything people did on their own initiative to improve job-related knowledge or skills: attending a school, taking a course, reading, or studying alone.

The analysis covered about 10,000 regular employees. About a quarter of them (25.6%) did some self-study in 2015.

1. A simple comparison shows a gap. Average income growth from 2015 to 2017 was 5.2% for those who did self-study and 3.4% for those who did not.
2. The gap survives basic controls. Comparing people with similar gender, age, education, working hours and company size, and then also similar school grades at age 15, position, industry and occupation, those who did self-study still had faster income growth.
3. The gap disappears with job quality and attitudes. When the comparison also matched people on eleven items such as “I could decide how to do my work,” “I felt I was growing through my work,” and “I could see my career path ahead,” the statistical difference vanished.

The author concludes that over a two-year period, self-study does not necessarily come with higher pay.

What kind of learning was linked to pay

The study also asked who was more likely to see a link. According to the text, among people who had studied natural sciences at university, the link between self-study and income growth tended to be stronger.

The author also interviewed ten male regular employees who said their self-study had “clearly led to higher pay.” Three paths came up most often.

• Allowances for qualifications. Language scores or IT certifications brought a monthly allowance.
• Payoffs that came later. Knowledge not studied for any immediate use, such as bookkeeping, broadened their role years later and led to promotion.
• Learning around one’s specialty. Technical specialists often did not deepen their core expertise but learned neighbouring areas, such as bookkeeping or law, and applied them at work.

How to read it

This is observational research, not an experiment. It may simply be that people in jobs where they feel they are growing both study more and see their pay rise. The interviews only included people who said things had worked out, so the stories of those for whom it didn’t are missing. You cannot read this as “do self-study and your pay will grow.”

Still, two hints — making learning visible through a qualification, and widening the area around your specialty — echo what studies from the UK and Germany found.

A small step for today

After you tick “Studied for 30 minutes” in the app, use “Wrote one line on today’s progress” to note where at work today’s learning could be used. If you are studying for a qualification, note how much of the syllabus is left; if you are learning around your specialty, note one thing this knowledge could help with next week. Making your learning visible in your work is the most practical takeaway from this study.

Sources

• [C4] Sakamoto (2018) The effect of self-development on the wages of regular employees (正規雇用者の自己啓発の実施の有無が賃金に及ぼす影響について). Works Review vol.13, Recruit Works Institute.