Yes, it does. Here are five reasons why.
1. Teachers who have previous experience with that grade or course are more effective teachers.
It is an accepted truth (backed up with evidence) that experienced teachers are more effective teachers. Some studies find this improvement plateaus after the first few years, others find continuous improvement throughout a teacher’s career. You could argue that schools could simply hire experienced teachers; there is no need to retain them. However, experience with a specific grade or course matters more than general teaching experience; teachers hired to a new school will not necessarily teach the same grade or course as they did at their old school, or even the same curriculum (especially for international teachers).