Piketty logic assumes infinite demand. Housing demand is very large, large enough to seem infinite when North American cities have spend 100 years banning every form of housing imaginable except the single family house, but it is not actually infinite.
If Piketty was correct, then inflation adjusted housing cost per sqft floor would always go up everywhere all the time. But we see dramatic differences in different periods of history, between different cities and we see rents stabilize & decline after building booms. We see housing costs go up the most in the places that build the least and the least in places that build the most.
If Piketty was correct, rich people could do this with things other than housing - they could buy cars and rent them out and then reinvest the profits to buy more cars. Ofc this doesn't actually work because there is no scarcity of cars - for better or worse we have chosen to place almost no limits on the quantity and density of cars in any city, state or country, while placing extremely tight & arbitrary limits on the quantity & density of floorspace in every city. For every car a rich person buys up to rent out, a car company reinvests the profits to build 1 more and then some. There is no functional reason residential floorspace cannot be exactly like that.
The housing market is much more inelastic than eg. the cars market. Whether demand in housing is infinte is a question of scale of population and wealth growth and elasticity. With that given, i would assume the postulated effect of run-off construction and renting, but we only have poluation growth and not the other two.
Just off the top of my head I can think of plenty of functional reasons why residential floor space cannot be analogous to cars.
Most importantly location matters. Space and buildings are not something that you can easily ship from one market to another to balance supply and demand. Space is inherently limited and replacing existing buildings with new more efficient ones is also problematic when you have people happily living in those old buildings, especially in high demand areas. Construction work takes time and in the meanwhile the displaced families will create even more demand.
There are practical limits on how densely you can pack floor space before it becomes prohibitively expensive, unsafe, or simply impractical. As you build higher the costs grow exponentially while the livable space per floor keeps decreasing due to the tapered shape of the building and need for larger structural core and more elevators. Above certain height you will be forced to target wealthier residents which means either offices or large luxury apartments that are anything but space efficient.
Construction is extremely capital intensive. A building takes a large upfront investment, and it takes a long time for it to pay off. With cars the cost of making more is marginal once you have an assembly line in place so it's significantly easier to re-invest profits into ramping up production.
Renting real estate makes more sense than renting automobiles because real estate is more expensive, less liquid, and better at holding its value over time. Owning a house is more difficult even when it would make financial sense to do so (not everyone can get a mortgage, or commit to living in the same city for an extended period of time).
> for better or worse we have chosen to place almost no limits on the quantity and density of cars
Even worse, most places have chosen to place a lower limit on the quantity and density of cars through parking mandates. It is absolutely insane that we are still wasting space on parking even in densely populated urban centers where it's impossible to accommodate everyone commuting by car.
> Space is inherently limited and replacing existing buildings with new more efficient ones is also problematic when you have people happily living in those old buildings, especially in high demand areas. Construction work takes time and in the meanwhile the displaced families will create even more demand.
The main reason old buildings with lots of people are replaced with somewhat taller new buildings, is because of bad laws that require new apartments to go only where old apartments already exist. IMO these are exactly the laws that need to be reformed and or abolished. It doesn’t mean that no one’s old apartment building will ever be demolished for a new one, but right now that’s effectively a requirement. If you want to add four space to a city, you are first required to demolish a large amount of apartment space, and evict everyone inside. If you could simply purchase a house that was already on the market, whose owners wanted to sell and didn’t want to live there anymore, and replace it with an apartment building he wouldn’t evict anyone. This transaction was once common place, but is now effectively illegal almost everywhere in North America because “house people” demand segregation from apartment people.
> There are practical limits on how densely you can pack floor space before it becomes prohibitively expensive, unsafe, or simply impractical. As you build higher the costs grow exponentially while the livable space per floor keeps decreasing due to the tapered shape of the building and need for larger structural core and more elevators. Above certain height you will be forced to target wealthier residents which means either offices or large luxury apartments that are anything but space efficient.
All true, but these limits are really only relevant or binding in Manhattan and perhaps one of two square miles worth of downtown cores in a few large cities. If someone wants to say that Manhattan will always be expensive for those reasons, that’s fine, but it’s no excuse for the other 99.99% of places people want to live in.
Reforming land use successfully IMO doesn’t require us to solve the problem of “how to make Manhattan (or places like Manhattan) even taller” but the much more economical goal of “it should be legal to build a 4 storey walk up with no parking, anywhere you can build a house.” That’s a tough political goal to be sure, but it doesn’t come close to having to deal with any sort of physical or efficiency limits regarding construction of very tall buildings.