For their studies, they borrow from the state. Then they pay their debt through 50% income taxes, limited to 7 years. If they get a bartender job with their engineering degree, they can still survive. Therefore studies are not free, they still have the responsibility of choosing right, they're not choked with debt and they still get a margin if they get a good job.
As an Australian currently paying off his education, this isn't accurate.
Firstly, there's no time limit. You need to pay back all of it.
Secondly, it's not a 50% tax rate. It's a additional % (4-8 %) on top of your normal tax rate, depending on how much you earn. There's also a threshold, so if you earn less than about $54k, you don't pay it back. At least, not that year.
Edit: Although I do agree with you: The answer is in Australia :)
Anything free creates a perverse incentive. Each year wagons of French students get graduated with History degrees at the free university. What job do they really intend to perform, how do they plan to contribute to society and how do they plan to earn money to give it back? How many historians do we really need? Most of them go straight to unemployment benefits for years. Which I also pay for.
I mean it has to be easy to study, like in Australia, but students need to be responsible with society's money, therefore it shouldn't be free.
For their studies, they borrow from the state. Then they pay their debt through 50% income taxes, limited to 7 years. If they get a bartender job with their engineering degree, they can still survive. Therefore studies are not free, they still have the responsibility of choosing right, they're not choked with debt and they still get a margin if they get a good job.