"the law reduced average test scores on the state’s standardized exam by approximately 20% of a standard deviation": https://www.sciencedirect.com/science/article/pii/S027277571...

"8 percent reduction in total compensation" https://www.cato.org/sites/cato.org/files/pubs/pdf/rb71.pdf

Not only does this hold up in general, it holds up district by district. Districts that still had collective bargaining had better scores than one that didn't (even after controlling for confounds, it was the union status that made the difference).

https://journals.sagepub.com/doi/abs/10.1177/0160449X1988337...

Not only that, teacher shortages are worse, and they're much worse in rural areas.

https://search.proquest.com/openview/5ae518d77f9e44551206208...

So the outcome is: Teachers make less money, there are fewer teachers to be had, and students are scoring much worse.

A win-win-win for conservatives!