Except that unlike a car, a house can be rented more easily and income gathered rather than sitting empty.

To rent out your Ferrari you'd have to run an agency and couldn't use it as you wanted to. Which kind of defeats the purpose of a luxury good.

I think it's more than just wear-and-tear... There are a lot of legal protections that make it hard to displace existing renters. Presumably most of these unoccupied homes are owned as rainy day assets, to either be sold or occupied in an emergency, and renters would limit this ability.

(It's hard to find data on how prevalent this is... From one article, it looks like a Palo Alto realtor estimated in 2015 that about 20% of home sales were to Chinese investors, with about half of these leaving the house unoccupied: http://sanfrancisco.cbslocal.com/2015/04/28/realtors-printin... )