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.
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.
- 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.
Instead people end up commuting longer distances.
(Not that London has any parking anyway)
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.
Be careful, those professional renters may be more professional than you want!
NYPost might not be top of its game anymore, but it still delivers a great cover once in a while.