This wasn't addressed to me, but I read it. It is one salvo in an ongoing exchange between Kotkin and a group of his intellectual opponents like Yglesias and Florida, both of whom have responded to and rebutted points in his essays at different times. see eg http://www.thedailybeast.com/article...el-kotkin.html

I don't know about all North American cities, but certainly Toronto is seeing massive downtown housing expansion, including both condo towers and more child friendly street-level rowhouses. The prices are probably in a bubble, and I don't know if all planned future projects will be built or if the supply will soon outstrip demand, but so far the ones that are already built have all filled up.

It may be that we are at a point in demographic time where we have an excess of single or childless young adults and that suddenly in the next 2 or 5 or 10 years many of them will suddenly want to procreate and move out to Mississauga, but as wolfchild points out, even Mississauga isn't what it used to be, and is in the process of densifying and urbanizing.