Why do so many places in London owned by foreigners that never live there? As old Marx put it, a commodity has two values. A use value, and a exchange value.

Why do so many places in London owned by foreigners that never live there? As old Marx put it, a commodity has two values. A use value, and a exchange value. In the case of land, usage would mean building on it, farming it, or some such activity. But even if nothing like that happens, the exchange value remains. Meaning that someone out there is willing to trade you for it.