This study investigates the effect of teachers’administrative workload on their endeavor in
classroom instruction preparation from the perspective of sociology of education. It is
demonstrated that without controlling for proper confounders, any studies regarding the subject
may reach a wrong conclusion, which is often an opposite direction from true value. That is,
it’s been mistakenly believed that even though time is a resource limited by its scarcity,
investment of time in administrative workload increases the time for classroom instruction
preparation. To eradicate this spurious relationship, we shows that we can set a research design
similar to an experimental one using an instrumental variable such as homeroom teacher. This
study proves that teachers’assertion that their time spent for administrative workload hinders
their essential works such as classroom preparation is quite reliable. In fact,
teachers’administrative workload becomes an opportunity cost for classroom instruction.
Furthermore, our findings depend on whether the school is public or private, and they are only
significant for the cases in public schools. Teachers in public schools are more likely to
consider administrative workload equivalent to classroom instruction. The critical reason is that
teachers in public schools prioritize bureaucratic needs, while sensitive to bureaucratic
responsibility, compared to those for students and parents. This study has a theoretical
importance in that it introduces new focus on studying issues related to organizational
sociology. Practically it suggests that more efforts to cut administrative workload should be
placed on public school than private school.