[derefr]

Laundering is needed if you want to (enable the people you trade with to) ever spend the black-market money on white-market goods.

Without that, your trading partner ends up holding a "dirty" wallet — just as if you gave them a suitcase full of marked bills.

That wallet still holds value — all dirty money does — but it's a lot less value than cleaned money.

Databases of stolen credit card numbers sell for not-much money. It's not just because you need stuff set up to drain the cards; it's because the money you drain from the cards is dirty. The dirty money is worth only about as much as the database itself. It's when you clean it that it attains "face value."

[rokobobo]

And the idea with stolen art is that "dirty art" should theoretically always trade at roughly the same discount to "clean art," and in fact, over time, as gaps in the provenance become easier to patch up through fabrication, the discount should reduce. In that sense, "dirty art" is an investment, so the immoral of the super-rich are fine holding it forever. Also, no need to pay estate taxes if it's already an undisclosed asset on a yacht somewhere.