True, but the constraints to construction and therefore to densification - particularly in the Bay Area - are immense. When it's hard to build in the city and

True, but the constraints to construction and therefore to densification - particularly in the Bay Area - are immense. When it's hard to build in the city and it's the urban fringe is a miserably long commute away - housing prices go up. When it's hard to build in the city and the urban fringe suddenly looks feasible, because traffic moves faster - you see city expansion.