So the source for this (which is stated and linked in the article) is something called the Zumper National Rent Report [1]. For anyone curious, this is their methodology [2]. This seems to be a measure of active listings based on advertised prices. So it's not necessarily an indicator of if those listings close and at what price (eg in hot markets, people can offer above the listed price). But it seems reasonably well-regarded.

I'm not sure where the "19 of 20" comes from because I grabbed the data from the report into a Google Sheet and sorted and it's not #19 by 1br Y/Y, 2br Y/Y or average rent. What it shows is 1br -5.6% and 2br -7.5% Y/Y. LA was -3.6%/-2.5%.

It's hard to find a comparable city to this because there aren't actually a lot of coastal cities in the US that aren't mega-cities (eg Boston, New York, Miami, Houston).

It seems like San Diego built ~4000 new housing units in 2025 with a population of ~1.4M. For comparison, Miami seems to have added ~18,000 but it's population also exceeds 6M so is that a fair comparison?

My point here is that the direct evidence linking building new housing units to changes in rent is weak.

Not that I'm opposed to building by any means but simply blindly building more units is by itself not an answer. It depends on what you build, where you build it and whether you allow effective or actual cartels to monopolize that supply.

Take Manhattan as an extreme example. There has been a ton of building along so-called Billionaire's Row and also some pockets in the Financial District, West Chelsea, the UES and so on. A lot of this stock is the so-called ultra-luxury market. Prices for some of these new units are now exceeding $7000/sq ft.

That is going to help absolutely nobody. Ultra-wealthy non-residents will park money there and that's it. This blind assumption that it will eventually become prole housing is ludicrous.

Housing should primarily be for shelter, not a speculative asset or investment vehicle to get wealthy by denying someone else shelter.

[1]: https://www.zumper.com/rent-research/national-rent-report

[2]: https://www.zumper.com/blog/our-methodology-empowering-the-r...

San Diego rents declined more than 19 of 20 top US markets after surge in supply