Tyler Cowen was recently asked how he’d best use a time machine for financial gain. Here was the specific query:
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?
Cowen notes some difficulty with an obvious approach:
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 establishing present ownership of a past item is an issue…as is authentication via carbon dating. I don’t have a specific scheme in mind, but I would think any general approach would also need to minimize the butterfly effect of your trade so that, for example, your existence in the present is not disrupted. So you can’t trade Leonardo an iPhone 6 for the Mona Lisa. But maybe you could trade $1 for a winning ticket for last week’s $300 million lottery jackpot…or would the numbers change somehow because of your visit? What if you bought 100,000 shares of Apple stock in 2003? How would that action effect the present? What is a large enough action to make you rich but with a small enough effect to keep the present otherwise unchanged? Since I didn’t see any super-compelling solutions in the comments at MR, I’m gonna open the comments here…I know someone has been thinking about this extensively or has a link to a good discussion elsewhere. Please stay on topic, mmm’kay?
This thread is closed to new comments. Thanks to everyone who responded.