Lots of people quoting basic supply and demand.
People in the year 1500 could pretty reliably tell you that a rock would fall down if you released it from a height. People would also tell you that if you threw it up and away, it would go up in an arc and fall down.
The innovation that Newtown and friends brought about was they made quantitative predictions about the rate at which the rock would fall down, or the arc it would follow - both to pretty high level of accuracy.
The point is that, of course, building more houses has a tendency to reduce rents. The question is whether reduction is -0.1% or -10% or there is an increase of +5% because some other factor was more dominant. It would be very hard for policy makers to argue against building more housing, if there was a quantitative model that predicted exact numbers for how much rent fell down given all relevant factors, and this model had been validated over and over again by prediction (not retrodiction). Rather than "rock fall down if you drop it" model that everyone keeps quoting.
Most rent payers aren't concerned with the exact function that will describe the shape of the curve for decline in cost of rent.
They are mostly interested in "rent go down", or at least "rent not go up".
That said, there are people who have studied this. You don't need Newtonian level math to calculate elasticity. Hell, we can look at how rents rise in a constrained market and make a pretty good guess what would happen if supply increases.
There are dozens of papers that have these numbers when you search the academic databases for "rent elasticity"
I don't think the predominant factor causing pollies to shy away from increasing housing supply is a lack of understanding that supply decreases prices, it's a lack of political will to decrease prices.
It's harder than you think to argue for a house price decrease when it's the singular asset that most older adults have most of their wealth tied up in.
Notably, though, a significant fraction of people seem to believe that building more housing will cause rents to increase. So it seems like it is still important to point to data suggesting the opposite.
> It would be very hard for policy makers to argue against building more housing, if there was a quantitative model that predicted exact numbers for how much rent fell down given all relevant factors, and this model had been validated over and over again by prediction (not retrodiction).
Policy makers are experts at completely ignoring objective facts, why would this be different?
We don't need to know how much. We just need to know the direction, and stop caring so fucking much about rich people going underwater on their home.
We don't need quantitative models if we want the rock to fall. It might be nice to have them, but one of the great things about market economies is that we don't micromanage according to overly complex estimates, and get better results.
Zoning and homeowners are holding on to the rock with a death grip, all while saying "the rock won't fall if we let go, that's fake science, it's far more nuanced you see" as they lie through their teeth to make big profits and immiserate those who don't own land.