>It's certainly not cheaper, for developers, to build highrise aparments in the city than upscale tract homes on tiny lots in an exurb. Why's that? At the marg

>It's certainly not cheaper, for developers, to build highrise aparments in the city than upscale tract homes on tiny lots in an exurb. Why's that? At the margin, at least, it seems unlikely that this is the case - it's probably quite a bit cheaper to add an additional floor to a 50 unit/floor high-rise (when it's being constructed, not after the fact) than to build 50 detached single-family homes in an exurb, for example. It's true that externalities can be, well, externalized, but that doesn't mean the difference in absolute costs shouldn't be considered. At the end of the day, someone still has to foot the bill.