It's impossible to run the kinds of controlled large scale socio-economic experiments you describe. If we ignore the evidence that doesn't meet your high standards, we'll have no real world data.
> If we ignore the evidence that doesn't meet your high
> standards, we'll have no real world data.
I would also add that variable standards of evidence are a good way to allow your strongly cherished beliefs to remain unchallenged for a long time.There's things you know, things you don't know, and things you think you know but you don't know. It's the last one that harms the most.
* No comparison with other countries, and their respective policies.
* No data on where these students graduate from, or in which subjects, or with which grades, or what their average salary is X years later, or whether they'll actually be able to pay back the loan.
It's missing a huge amount of important information; you really can't justify the conclusion "tuition fees are good" from this alone.