Impact of PhD Supervising Setting: A Comprehensive Analysis based on "Japan Doctoral Human Resource Profiling, JD-Pro"

PhD training in academic labs offers the foundation for the production of frontier knowledge workers, indispensable for the modern knowledge-based society. Nonetheless, our understanding on PhD training has been insufficient due to limited access to the inside of academic labs. Furthermore, early careers of PhD graduates are often difficult to follow, which makes the evaluation of training outcome challenging. To fill in these limitations, this study aims to illustrate the settings of PhD training in academic labs and examine their impact on several aspects of training outcome, drawing on "Japan Doctoral Human Resource Profiling", a national survey of a cohort of 5000 PhD graduates from Japanese universities.
Our regression analyses controlling for several variables indicate the following results: (1) PhD students who received frequent instruction by their official supervisors are likely to successfully earn degrees and engage in jobs related to their dissertation subjects; (2) frequent supervision by internal faculty members is associated with high performance both in academia (based on publications) and in industry (based on wage rates); (3) frequent supervision by external faculty members is associated with successful degree attainment and academic career choice; and (4) frequent supervision by non-faculty members (e.g., postdocs and senior students) is associated with non-academic career choice. The expansion of postgraduate education since 1991 has increased the number of students per supervisor, which has added to the workload of faculty members, along with other duties such as administration and fundraising. The result indicates that frequent supervision by multiple faculty members improves career outcomes and students' satisfaction, suggesting the need for secondary instructors as well as expert staff supporting faculty members.