Well, in this one I don’t think I really addressed either supply or demand; I don’t think I made any strong statement about preferences or causes here, just trends.
But broadly speaking, my understanding is that recent construction has been rather more robust in high-density areas than lower-density areas. I’m not sure whether there’s been a major supply shock that would cause urban areas to shift from massively undersupplied before 2007, oversupplied until 2011, then undersupplied again after 2011? Supply constraints tend to be very long-term; really generally any supply-side reasoning is long-run reasoning. These are short-run changes I’m describing in this post.