[ProfessorLayton]

>Yet the rent in Paris is still too high for an average French resident

It's obviously not just about more housing, but more housing per capita.

3% of the French population lives in Paris proper, and roughly 20% in the metropolitan area compared with 0.42% in San Diego and ~1% in San Diego MSA [1].

More hosing will help Paris along with San Diego to put downward pressure on prices.

[1] Wikipedia