On your point of what could “governments do”… They could increase down payments!

Indeed. Canada could:
1. Increase down payments
2. Lower amortization times (from 25 to 20 years)
3. Raise stress tests
4. Bring in capital gains tax on all real estate: Hong Kong style … sell in 1st year – tax 50%, 2nd year 35%, 3rd year 15% etc.

Rest of the world?
New Zealand: Raises down payments for investment real estate to 40%!
As of May, most buyers who plan to live in their home will be required to provide a down payment of 20 per cent. Investors will need to put down 40 per cent.

China to slow lending: Larger state banks are required to limit their outstanding property lending and mortgages to 40 percent and 32.5 percent of their total loans.

China DP on first house 25% on second house 40%. In some areas that overheated its markets…DP are as much as 60%.

Funny, yet not really: Chinese authorities crack down on ‘fake’ divorces.
Since in some areas, second homes are not allowed some Chinese fake divorces to get to buy 2 properties!