I mean the most important factor is the students and their backgrounds. Lots of places will never have good schools or will always have high ranking schools due

I mean the most important factor is the students and their backgrounds. Lots of places will never have good schools or will always have high ranking schools due to the kids attending just being smarter or less so. That said, the research is quite clear that unions hurt student performance, and if your only goal is improving student performance non-union charter schools seem to be the best option. By giving parents as much choice as possible, parents tend to pick better schools, and poorly run schools are force to lay off staff or go out of business, so better run schools can replace them.