In 2018 state Reps. Margaret Doherty, D-Portland, and Brian Clem, D-Salem, introduced legislation requiring the state’s school districts and teachers to make class size part of the collective bargaining process. It passed in the House but died in the Senate.

Doherty is back this year with House Bill 2526, nearly identical to the 2018 bill. No doubt she’s hoping the strength of Democrats in both houses of the Legislature will be enough to carry the bill over the finish line this time out.

The measure was bad in 2018, however, and it’s just as bad today.

Supporters of the idea will tell you that the smaller classes they hope would result from bargaining the issue are better for students. That’s true, sometimes and for some students. But research on the impact of class size on learning is far from unanimous, and the parts of the single randomized control study done have since been challenged. At the least, the measure likely would mean more money in teachers’ pockets.

Meanwhile, like it or not, smaller classes mean more teachers, and while that’s not necessarily bad, it does drive up the cost of education. Class-size legislation in California, for example, adopted in 1996, proved to be so expensive that, after it limped along through the Great Recession, the state abandoned it in 2013.

Some Oregon lawmakers are aiming for as much as $2 billion more to the state’s secondary schools in the 2019-21 biennium. Some of that may will go to help pay down school districts’ Public Employees Retirement System unfunded liabilities or, at the least, to backfill for money already being used for that purpose. And some may be used to cut some class sizes.

But class size is not the answer for all children, and perhaps not even for all younger children. The state, its children and taxpayers would be better off not mandating that class size must be bargained.