Joe Nathan

Joe Nathan

They teach math in charter schools, but the numbers don't always add up.

A new report by the National Alliance of Public Charter Schools puts charter school enrollment in Minneapolis last school year at 9,339 and in St. Paul at 8,776.

That's quite a difference from numbers reported by the St. Paul-based Center for School Change just last June.  That group reported Minneapolis charter enrollment of 11,125, and St. Paul enrollment of 9,014. The center's numbers are based on Minnesota Department of Education numbers and were compiled after consultation with department enrollment specialists. The alliance's numbers are be based on the federal National Center for Education Statistics.

There are many many ways to count charter school numbers.  A simple way is to add up the enrollments of charter schools located in a city. But the national report decided to exclude charter students who are enrolled in a virtual,  or online, school, according to Joe Nathan, who runs the center, did the state report, and spoke with the national report's authors.  

Turns out that exclusion can make a big difference in the numbers.  For example, the two entities differ markedly on charter school penetration.  The alliance claims a 21 percent Minneapolis market share for charters, compared to district schools, not counting private or parochial enrollment. But the numbers compiled by the local center put the Minneapolis charter market share at 33.2 percent of district enrollment. For St. Paul, the alliance calculates a 19 percent market share, compared to 24.3 percent for the center. 

The alliance ranks the Minneapolis market share 24th in the nation, and St. Paul 28th. But they're the lowest among big cities in the Midwest aside from Chicago, despite Minnesota's 20-year history of charter schools.

There's more agreement on statewide numbers, where the two groups are only 14 students apart.  The alliance puts enrollment at 39,143..