You are disregarding supply and demand because it's not a 100% bullet-proof model that can predict all price movements in all markets, times, places, or any combination of factors, and at the same time are introducing your own imperfect models and formulations:
> For example: more supply can generate more demand. Demand can be inflexible with respect to supply. Supply and demand are unstable and can change unpredictably. In a monopoly situation price can be manipulated. Short term large supply can hamper long term.
Any model that tries to predict human behaviour will be imperfect, we all know that.
There is hardly a monopoly of housing in Spain, if we keep the current disconnection between supply and demand, prices will for sure keep increasing. There is evidence that building more reduces prices. It's not the only condition needed to reduce prices, but it's an important one:
> You are disregarding supply and demand because it's not a 100% bullet-proof model
I didn't any suggestion to "disregard" the "law of supply and demand". I saw a suggestion that whatever kind of "law" this is, it is a very different kind of thing than a law of physics, to which a comparison was being made.
> Any model that tries to predict human behaviour will be imperfect, we all know that.
Yet we can rarely even bound the actual scale of the imperfection, so discussing "laws" of economics as if they are in some way similar to the law of gravity seems a little silly.
> You are disregarding supply and demand because it's not a 100% bullet-proof model
OK. Can you provide me just one example of a large city that reduced the housing sale prices by building more dense units? Not by crashing its economy or otherwise decreasing the population.
If your model is correct, there should be at least _some_ examples.
> There is evidence that building more reduces prices.
There is none. Your studies are basically nonsense. Here's the strongest result:
> One study cited in her report found that the average new apartment building lowers nearby rents by 5 percent to 7 percent “relative to the trend rent growth otherwise would have followed”
Translation: the prices grew, but we managed to P-hack a small subset of data that shows at least _some_ effect. They could not find actual _decreases_ and had to resort to "would have beens".
Nope. Rents dropped because the _population_ in Austin dropped. It has recovered to 2019 level only the last year and is still below the peak 2020 level (stats are taken at Jan 1).
> For example: more supply can generate more demand. Demand can be inflexible with respect to supply. Supply and demand are unstable and can change unpredictably. In a monopoly situation price can be manipulated. Short term large supply can hamper long term.
Any model that tries to predict human behaviour will be imperfect, we all know that.
There is hardly a monopoly of housing in Spain, if we keep the current disconnection between supply and demand, prices will for sure keep increasing. There is evidence that building more reduces prices. It's not the only condition needed to reduce prices, but it's an important one:
https://commonwealthbeacon.org/housing/study-says-boosting-h... https://www.upjohn.org/research-highlights/new-construction-...