Ghis - I generally didn't take my kids into French bars, as I tended to lose them in the smoke fugg (even more that in England pre july). Be interesting to see how it has changed.
TJ, there is no doubt a magic formula, and a PhD thesis on this. I imagine a critical mass of kids is around 15% - well below what I witnessed in a pub in the Derwent valley today, and hence not overun