The thing about high rises is that they require money to put them up, especially in seismically active areas. Typically the cost is such that an apartment in a high rise takes at least several years to fully pay off when paying off a mortgage with payments of the equivalent of today's monthly market rent.
Relax regulations, clean out zoning, remove market controls, employ people on the black market, do the construction not-for-profit and you might be able to slash the cost by half or maybe two thirds, probably not more. (There is a finite amount of people willing to pay to live in such a high rise, but let's assume demand really is huge.)
In particular, even at that lower construction cost it won't be worth it for anyone to build if the rent is to be comparable to maintenance costs, whether through supply/demand or otherwise. This will be the case until you can put up high rises at a total cost of about $900-1200 per unit (roughly 15-20 times the monthly payment), no matter how many you can put up.
Relax regulations, clean out zoning, remove market controls, employ people on the black market, do the construction not-for-profit and you might be able to slash the cost by half or maybe two thirds, probably not more. (There is a finite amount of people willing to pay to live in such a high rise, but let's assume demand really is huge.)
In particular, even at that lower construction cost it won't be worth it for anyone to build if the rent is to be comparable to maintenance costs, whether through supply/demand or otherwise. This will be the case until you can put up high rises at a total cost of about $900-1200 per unit (roughly 15-20 times the monthly payment), no matter how many you can put up.