Time travel and currency.

I trip and fall into a wormhole. I end up in 2005. I have a hundred dollar bill from 2015 in my pocket. If I could convince people that I came from the future how would we value that bill so I could break it and have some walk around money?

There are plenty of bills still circulating that are older than 2005.

I’m going back n time not forward.

Since the bill cannot be used for 10 years, you have to calculate the “future value” of the bill and sell it at that value. It would have a negative future value (less valuable) based upon inflation for the 10 years.

If you could convince people you came from the future, the last thing you would have to worry about would be walking around money. You could make millions by selling information, but I suspect you’d not be walking around free.

Yes, but the bill in your pocket might be one of those old ones.

Pointless speculation. Why (even aside from convincing people) would a note from the future have any value. Maybe if you had a large number of them, you could convince someone to speculate, but I doubt you could do better that 10 cents on the dollar.

Way more than 10 cents on the dollar. It’s essentially a bond worth $100 in 10 years. At today’s 10 year bond rate of 1.9% it’s probably worth $80 or so.

“Of course it is a real bill!” says some guy who claims he’s from the future.

[QUOTE=The guy who wrote the OP]
If I could convince people I came from the future
[/QUOTE]
It’s stipulated in the question. How he convinces the person from the past is left as an exercise for the reader.

If I were convinced of the OP’s case and if only for a one-time deal, I’d give you 100 bucks. Dude, it’s money from the future. Assuming no other actions are posible (knowing Superbowl champions, lottery or stuff like that) that’s all I would do.
If it were larger ammounts it’d be closer to 50%.

Yeah, it’s really worth around $82 if held the whole 10 years at current bond rates, but a real 10 year bond is at least somewhat negotiable before maturity, and you wouldn’t be able to exchange it without convincing a buyer of its bona fides, so you’d want a premium for the lack of liquidity. I wouldn’t hold out for 50% though, I’d settle for 60%, and I wouldn’t want more than 30% of my money tied up in it.

From a practical point of view, have you ever seen anyone check the date on a bill before accepting it? It’d be better if you brought a $20 (a hundred might get extra scrutiny), but no one’s going to notice as long as it looks like the bills currently in circulation.

You might ask Paul Krugman, Nobel-winning economist who wrote a paper on the economics of space travel, taking the long time spans into account:

https://www.princeton.edu/~pkrugman/interstellar.pdf [PDF but worth it for the chuckles]

Well, yes, but the OP posits an accidental time warp with the time traveller not having advance warning of it. They have to go with what’s in their pocket.

If they have any twenties, they would be much better because in between 2005 and today, there was a new and rather different design of the $100 bill issued. The old ones look like this and the new ones like this. You’re not going to pass the new ones off as old ones.

I’m assuming the OP means they have one of the new ones. Unless you can convince people you come from the future, a new one is going to have the value of a curiousity, which probably won’t be very much. If you can convince them, then the bill may be worth what people are saying above. But everyone’s going to want to know who wins the Derby, Series, Superbowl, etc. for the next few years so they can win bets. Or they’re going to want to know what the stock market does and who’s elected president in 2008 and so forth. Instead of making the bets yourself, you could just sell that info to the highest bidder. Then you won’t need to sell the hundred.

So this is a good reason to carry a sports almanac around with you at all times.

You don’t even need specifics. Just tell them to short the S&P 500 around Christmas 2007 and then go long again in mid-2009.

The easiest thing to bet on would probably be the presidential elections (I mean easy in terms of ‘everyone’ knowing/remembering the outcome without needing a sports almanac or something like that).

If you can actually convince people of your story, an authentic bill with “2015” printed on it would sell for a sh*tload of money. Nobody would care about face value. Just put it on ebay.

It very well might, but its collector’s value might be damaged by the fact that it’s value will become null in ten years. Collector’s items don’t normally have an expiration date.

Frankly, I don’t see how you are going to convince anybody that this is legitimate legal tender from the future. More than likely, they will nod and pretend to listen while someone else calls the cops and report a counterfeiter. Then you will probably spend the next ten years explaining how you made a near-perfect counterfeit $100 bill, getting only the date wrong.

“Time travel? I love that story. Now tell me how you really made this bill.”