Traveling back into the past to trade for present gain

Does that blog post header meet the standards of Buzzfeed?  Not long ago I was asked this question in connection with a talk, but I didn’t have time to answer it:

Suppose you had a time machine you that you solely wanted to use for financial gain. You can bring one item from the present back to any point in the past to exchange for another item that people of that time would consider of equal value, then bring that new item back to the present. To what time period would you go, and what items would you choose to maximize your time-travel arbitrage?

The obvious answer encounters some difficulties upon reflection.  Let’s say I brought gold back in time and walked into the studio of Velazquez, or some other famous painter, and tried to buy a picture for later resale in the present.  At least some painters would recognize and accept the gold, and gold is highly valuable and easy enough to carry around.  Some painters might want the gold weighed and assayed, but even there the deal would go fine.

The problem is establishing clear title to the painting, once you got back home.  It wouldn’t turn up on any register as stolen, but still you would spend a lot of time talking to the FBI and Interpol.  The IRS would want to know whether this was a long-term or short-term capital gain, and you couldn’t just cite Einstein back to them.  They also would think you must have had a lot of unreported back income.

So here are a few options:

1. Find an artwork which can be marketed through the right private dealer, who will not ask too many questions.  Of course that means it will sell for much less, without reliable provenance, even if it appears to be fully real and indeed is fully real.  Furthermore depositing the check still will raise a lot of questions and invite a lot of scrutiny.

2. Find an artwork you might have some plausible path for owning, yet without paper record.  Would that mean visiting de Kooning and, upon your return to the present, claiming that Papa gave it to you right before he passed on?  That is still inviting lots of scrutiny and perhaps a polygraph as well.  Plus other people, still alive, knew Papa and know he didn’t have contact with de Kooning, and wasn’t holding “Excavation” up in the attic.

3. Search out a class of artworks for which provenance is a more or less meaningless concept.  But even then, you still need some story for how you came upon the work and how you could afford it.

OK, given all of this, what should you do?  I do not, of course, recommend hiring someone to forge the provenance papers.