Hierarchy may be determined by a respect for time.

A teacher's time is not valuable. Teachers are not compensated for the time spent preparing classes our carrying out routine functions.

In some cases, teachers are required to stay in school for certain periods, even if they have no work at that time. Other teachers have to report to school for a full day, even though they do not have to teach that day. They are told that they are being paid to be in the school.

Yes, teachers always have things to do. They can fill the time in a worthwhile manner. However, the schools do not always respect the teachers enough to allow them to choose where they will do their work.

Principals, on the other hand, have a demonstrably higher status. Those who are told that the principal is busy know that they must wait respectfully.