Your question is a little like asking "If chemotherapy cures cancer, then how come most people I know who have undergone chemotherapy tend to have cancer?" If the cities you mentioned hadn't undertaken some pro-density measures they would be even more unaffordable.

BTW if I sound like I'm anti-density because of the "cancer" metaphor, I'm not; sprawl is bad for the planet among other things, and well-planned walkable dense cities are the best way for a burgeoning human population to live in harmony with the planet and with ourselves.

No, its not like that. Dense, walkable cities create demand, chemotherapy doesn't create cancer. If LA were to create an ultra-dense core tomorrow, more people and companies would relocate there, bringing rents right back to the level they are now, probably higher. The only people losing out would be existing low-income people who got displaced.

NYC concrete jungle = "live in harmony with the planet"? Lol.

Because people are willing to pay more to live there. All of those places are distinctive because their environments are illegal to build now, so we haven't made more of them even while population grew and urbanized.

In a nutshell, because suburbs are boring.

They're low density even if you account for increased travel radius due to cars. That means you have a smaller concentration of people for events/stores/restaurants/etc. which means you have fewer events/stores/restaurants/etc. Especially once you move away from the most common mainstream events/stores/restaurants/etc since those cater to a much smaller subset of the population (which in suburbs is too small to sustain a business).

> They're low density even if you account for increased travel radius due to cars.

What does it mean, exactly? How do you "account" for the increased travel radius? Do you divide by the distance or by the distance squared? Are you sure that in both cases the density is low? It does not seem so, to me.

In the case of London an in important factor is because many people are using housing stock as an investment opportunity, rather than a place to live.

More empty home taxes and secondary home taxes.

And make property taxes progressive. The first 100k in value is tax free, then a higher rate on each progressive 100k.

Make it so locals love it when a billionaire buys property in their neighbourhood and doesn’t live in it.

Excellent ideas, doubt the billionaires will go for them. Or even the top 10% of voters. The UK's capped property tax is ridiculously regressive.

(Not that London has any parking anyway)

> More empty home taxes and secondary home taxes.

Then "professional renters" will appear, one person renting and living in a 20 room apartment, and the actual rent money will come in a convoluted way from the billionaire.

At least where I am (Ontario Canada), once you lease it, you can move in as many people as you like as long as it’s not a health violation.

Be careful, those professional renters may be more professional than you want!

Like this (from just a week or so ago) ? https://nypost.com/cover/covers-for-saturday-august-17-2019/

NYPost might not be top of its game anymore, but it still delivers a great cover once in a while.

The uk already has a fairly progressive property tax call stamp duty and many councils in the UK have property taxes (or at least our equivalent called council tax) for empty properties. The problem persists not because of billionaire investors but due to:

- Easy capital access in the form of cheap buy to let mortgages. Easy access to leverage mean property out performs pretty much every other investment and much of the middle class can afford it.

- Lack of regulation on tenancies. Very very easy to kick people out and up the rents.

- General shortage. The uk simply doesn't build enough houses. This is made worse by many jobs existing primarily in London / many graduates not realising that there are opportunities outside of London.

Stamp duty is not a proper property tax because it's only paid on transfer of the property. I'd quite happily abolish it in favour of a true annual valuation-based tax. Besides, it's quite easy to evade: have the property be owned by a shell company in an opaque jurisdiction. Sell the company.

And it discourages/punishes people from moving to the right home for their changing family size/situation and changing job situation.

Instead people end up commuting longer distances.

Stamp duty is only levied at sale, that is hardly the same thing as is usually understood by property taxes. Council tax is absurdly regressive (intentionally so).

Council Tax is paid by the tenant. This does not discourage the wealthy from hording investment properties.

If you hold property that's not inhabited you pay council tax on it. It's a less than ideal tax but it does tax property hoarding.

Density can increase desirability, increasing demand beyond supply causing prices to rise. Also, as a selection bias we only hear about the really popular expensive cities and not the cities that are dense but less desirable and hence affordable. For every Hong Kong there is a Dongguang.

I can't find a source at the moment, but I have to believe there are more affordable housing units in Manhattan, SF, London and Hong Kong than in most other places in the world. Do you agree?

Hong Kong? Definitely not. London also looks pretty terrible (affordability-wise). SF surprised me but its probably just because local incomes are so high.[1]

This Tableau/OpenStreetMap chart isn't quite displaying correctly for me but it paints a bleak picture of California's affordability. Not sure if you can scroll over to NYC.[2]

This last source has London, NYC, and HK all in its "most expensive" 5 (from an odd assortment of cities) for rent-to-income ratio.[3]

[1]https://www.numbeo.com/property-investment/gmaps_rankings.js...

[2]https://www.cnbc.com/2019/03/07/heres-the-share-of-income-th...

[3]https://www.weetas.com/article/rent-income-ratio-17-major-ci...

I'm not talking about average rent. I'm talking about supply of affordable housing units.

45% of Hong Kongers live in public or subsidized housing.[1] That's over 3 million people. That's a lot of affordable housing, in a very dense city!

You suggested suburbs would be better. Can you name any city's suburb(s) that has enough affordable housing for 3 million people?

[1]https://en.wikipedia.org/wiki/Housing_in_Hong_Kong

>>>Can you name any city's suburb(s) that has enough affordable housing for 3 million people?

Sure: Yokohama, if you'll accept a city of 3.7 million as a "suburb" of a city of 14 million+. Just as a rough guide, compare these two results: [1][2]. The lowest Yokohama rents are HALF of the lowest HK ones, and I'm fairly confident that lower-class/lower-middle class incomes are not doubled in HK.

[1]https://realestate.co.jp/en/rent/listing?order=12A&page=1&pr...

[2]https://www.squarefoot.com.hk/en/rent/list/?sortBy=price-asc

Your comment reminds me of the parable about the dictator who noticed that the provinces with more sick people had more doctors, decided that doctors were the cause of illness, and summarily had all the doctors executed.

Try and use a little common sense about the direction of cause and effect here.

The other comments in this thread got most of it. But let’s also remember the other side (suburbs) are heavily subsidized by urban communities.