The revenues of Michigan school districts are directly linked to enrollments: More students means more money for a district's operations, and fewer students means less.

In Michigan, enrollments are falling in many if not most districts, which means that labor costs must also be trimmed. The process of trimming can pit different school employee groups against one another.

The graphic below is from a presentation made by the Port Huron Area School District board and shows (in more ways than one) how this process often plays out.

PH Employee Costs

The Port Huron Education Association (PHEA) is the union that represents teachers and certain other employees. Although its members only make up 60 percent of the district's labor force, they consume almost 77 percent of total labor costs.