[foxyv]

Unfortunately there is much more to the story than a number on a line. Just because you increase spending doesn't mean that the spending isn't earmarked for items like digital projectors and virtual textbooks that have minimal impact on learning outcomes.

[zaphar]

So theoretically if your spending was hiring more and better teachers and better HVAC and more/smaller classes then spending would and has experimentally been verified to have an impact. Especially if you also paired it with getting rid of teacher who don't meet the bar.

But as a practical matter that is not what happens when a campaign to increase funding for a school happens. The problem is not insufficient money, the problem is not enough skill and political will in how you spend the money.