[jjav]

> "density didn't solve anything!"

It's worth asking, does density solve high cost? Is there evidence for that?

The first reaction is sure, supply and demand. Dense means more supply thus lower cost. But density also brings induced demand.

Where are these very dense cities that are also very cheap?

The two densest cities in the USA are NYC and SF. Neither is known for cheap housing.

[zjp]

Well, in 1920 to live in Midtown you would have had to be able to drop $3m ($55m inflation adjusted) for a ground-level mansion and now you can get an apartment there for under $1m, so I would say the cost has dropped precipitously over the past hundred years.

Demand is only induced when you give the thing away for free.

[jjav]

I don't know where to find rental pricing info for 1920s NYC so can't really check. But I'm fairly confident that $55M (inflation adjusted) was not the cheapest apartment available at the time so it's not an apples to apples comparison.