[Kadin]

> How is it possible that these properties are not being rented out?

Maybe they are, and it's just all being conducted on a cash basis. Or if a Chinese owner is renting to another Chinese expat, they could be handling the rent payments in China (advantageous as it avoids moving the money outside China, which I am led to believe can be difficult and is one reason for the complex real-estate-based 'money parking' schemes in the first place).

The tax on "vacant" properties should probably be set equivalent to the income tax that one would pay on the average rent that you could extract from the property if it were fully rented. That would discourage actual vacancy and eliminate much of the incentive to have under-the-table renters.