You could also say the battle is already half lost. If you don't contest the productivity issue, you lose the rest too. There is no real disagreement that education is important. To the contrary, the scuttlebutt is that it is more important than ever. Farmer Perelman mentioned this. I alluded to how income growth could be expected to increase demand.
The real issue is public v. private. The cost disease lit does not grant any advantage to private providers. The same factors reduce productivity in private schools and make them more expensive too.
mbs