Oregon struggles at near bottom in high school graduation rates, and the state’s absenteeism is through the roof.

A group of legislators led by Democratic Reps. Brian Clem of Salem and Margaret Doherty of Tigard have proposed to make education in Oregon better by mandating class size be negotiated in labor contracts. House Bill 4113 would make class size a mandatory subject of collective bargaining between teachers and school districts.

It’s not completely unreasonable that class size be included. It’s included in the collective bargaining in other states. But the only clear thing the bill would do is strengthen the power of teachers’ unions. Legislators should vote ‘no’ on HB 4113.

Class size is excluded by law from collective bargaining in Oregon along with a long list of other items — teacher evaluations, dress, grooming, smoking, student discipline, the time between classes and more. The most curious exclusion under Oregon law must be “gum chewing.”

It’s taken as almost a given in education that smaller class size is better. There would be less chaos and more one-on-one time with the teacher, right? Years ago, a key study in Tennessee “proved” smaller is better. But that study had holes. And when schools go gonzo for smaller class sizes, it means something else suffers. Reducing class size is actually one of the most expensive ways to improve education. Some states — California, Florida and Wisconsin — ratcheted back after trying to dramatically improve class size because of costs and lack of sufficient improvement.

HB 4113 seems more like an effort to deliver a boon to teachers’ unions in Oregon than an effort to improve education. The Oregon School Boards Association fears it will add costs and lead to other cuts without necessarily improving education.

If there’s anything education research is clear about, it is that the single best way to improve student performance is improving teacher quality. But instead of a bill aimed at that issue, Clem and Doherty crafted HB 4113 to strengthen the power of the state’s teachers’ unions. Vote it down.