Many of those cities are only in the last few years returning to their peak populations. They certainly aren’t more dense, but there are fewer units of housing

Many of those cities are only in the last few years returning to their peak populations. They certainly aren’t more dense, but there are fewer units of housing available now. In many places lots of housing was torn down, or multi family homes were turned into single family homes. The cost is directly related to the fact that it is defectors illegal to build new homes in the most economically vibrant zip codes.