In my school, the class monitor changes every month. Is that what you call a power-sharing arrangement?

Power sharing means when power is not concentrated with one organ or with one person rather is equally distributed.

Distribution of power helps in effective monitoring and enhancing accountability in any system.

The class monitor is the one who has a bit, more power over the class. He /she are appointed by the class teacher to maintain discipline in the class when the teacher is not there. Hence power is given to the monitor to monitor the class. By changing this monitor between the students, power is given to each one to guide the class taking responsibility. This will make them vigilant about the use of power.