The question is - those that are not in the active population - is it for good reasons like studying, or is it because they are discouraged?
See this:
Translated and discussed here: Facts about the French labor market In the long run, we're all dead. John Maynard Keynes
However, this graphic was somewhat helpful to me:
It seems to indicate that if you are under 26, and do not have a technical or professional degree (Bacs professionel ou technologique), then you will have a higher chance of obtaining a permanent work contract (CDI) if you continue studying until you get a "graduate degree" (Deuxième cycle), and even more chance with a post-graduate degree (Troisième cycle) -- assuming I'm reading it right.
If that is general knowledge young people, and if higher education is free (which I believe it is in France by and large), then presto, you have 60% of 15-24 year olds enrolled in school trying to get higher and higher degrees.
The chart would help a lot more if it gave percentages of people who have each respective level of education. I encourage you to go shopping more. -- George W. Bush
