[chongli]

Should I be able to tell you how to use your computer, phone, or car?

No. Land is different from all of those other things. We can always make millions more cars, phones, and computers. We can't make millions of additional housing units in economically important cities like San Francisco, New York, Vancouver, Toronto, etc. So it behooves us to make sure that housing in those places is being used efficiently instead of sitting vacant. That's all there is to it.

[tomcam]

Let's use your house more efficiently. If you live in the United States, I bet you have a house that could fit at least two more families in it. Do you mind if I move in some of my relatives? Or, more specifically do you mind if your neighbors passed such a law?

[snrplfth]

We can stack houses though. That does work pretty well.

[chongli]

It works pretty well in theory, not so well in practice. Too many issues with neighbourhood associations, land values, zoning, infrastructure, etc. It actually turns out to be very hard to increase the housing stock in a lot of major cities.

[snrplfth]

I'd say it's overwhelmingly due to the regulatory straightjacket these cities are caught in. Municipal and regional governments have made it extremely difficult to add new housing through increased density, and then they find that prices are climbing sharply, and wonder "how did this happen?!" Well, supply was choked off.