Best choice

A puzzle showed up in my Facebook feed. Two doors. One says you get one billion dollars right now. The other says you get a dollar right now, but it doubles every day. Which do you pick?

Three ways to choose come to mind. The mathematically naive will pick the billion right now, figuring that the other would take too long to do anything useful. Somebody with a little more math, but economically naive, knows that in a month the doubling dollar will grow to be more than a billion dollars (except in Feb, where it's only 268 million or 536 million in leap years).

But the third way notices that in 40 days the value of that dollar becomes over a trillion dollars, and in 50 days each dollar will have started to lose value since there'll now be $1125 trillion to chase only $113 trillion of world GDP. A dollar will then be worth 10 cents, and in another ten days a hundredth of a cent. You can safely assume that panicked hyperinflation would cause everybody to just abandon the dollar entirely.

Or you could decide that neither selection would be good for you and be content with what you have. (Is that playing fair?)