Ian McKenzie's Shortform

Ian McKenzie

This is a special post for quick takes by Ian McKenzie. Only they can create top-level comments. Comments here also appear on the Quick Takes page and All Posts page.

John Wentworth says:

You will never find a $100 bill on the floor of Grand Central Station at rush hour, because someone would have picked it up already.

Are you really less likely to find $100 in Grand Central Station than finding $100 anywhere else? It's true that there are many more people who could find it before you, but there are also many more people that could drop $100. If you imagine a 1D version, where everyone walks through either Grand Central Station or a quiet alley along the same line, one after the other, then it seems like you should be equally likely to find $100 in either case – if the person in front of you in the line drops $100.

There's probably more "bill-spotting effort per occupant" in grand central than elsewhere in life. Like maybe at a random train station there is on average $10/day available for the world to make watching the ground for abandoned cash, while at Grand Central there is $300/day. It is worth ~nobody's time to just sit around looking for bills in the random case, but in the grand central case maybe there is a kid who decides to try. If a bill drops within 20 meters of that kid, they are pretty likely (say > 30%) to notice it before anyone else does — just b... (read more)

1Elliott Thornley10mo

Yeah I think the only thing that really matters is the frequency with which bills are dropped, and train stations seem like high-frequency places.

6omegastick10mo

In this scenario, are you not also also paying uniquely little attention to your surroundings (and thus equally less likely to spot the bill)? It feels a little like begging the question to apply that modifier to other people in the scenario, but not yourself.

Ian McKenzie's Shortform

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Ian McKenzie's Shortform

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