Let me repost my comment from the other thread here:

Those who can't make it into a Grande Ecole or can't afford (or don't make it into) the requisite école preparatoire between ages 18 and 20 will end up in the Universities. Which is why calling the university student protesters "elites" is disingenuous.

I also have a question: it is an accepted fact that there is no way to pass the Grande École entrance examinations without spending up to 2 years in an école preparatoire, which are by themselves quite prestigious and, while being arguably post-secondary education, are still considered pre-universitary (thus giving France an unfair advantage in the International Mathematical Olympiad, but that's another story).

Anyway, my question is, what access barriers (or unfair advantages for privileged children) exist at the level of the écoles préparatoires_?

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman