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Comment by milesvp | Hacker News Reader

Two economists are walking down the street and pass by a hundred dollar bill without picking it up. A little while later one turns to the other and asks “was that a hundred dollar bill on the ground?” To which the other replies “nope, if it was someone would have picked it up already.”

I’m with you, this joke haunts me daily. I studied economics in undergrad, and market efficiency is such a basic tenet that it’s really hard to see opportunities that don’t just look like a mirage.

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Two economists are walking down the street and pass by a pile of dog shit. One of them (a sadist) turns to the other and says "I'll pay you $1000 if you eat that dog shit".

The other performs an internal utility calculation and eats the dog shit.

Continuing their walk, the second economist sees another pile of dog shit and makes the same offer to the first. The first economist also agrees, and eats the dog shit. They walk on.

After a while the second economist says to the first "it feels like we're both worse off than we were before this walk".

The first economist replies "impossible! We've just engaged in 2000 dollars worth of trade!".

Ha! This is good! XD

The first one then replies: "no, you’re not getting it, it’s a VC funded business aggressively attracting customers"

This is quite a caricature of the profession. I studied economics in grad school and most of the time was spent discussing all the ways in which the market is not efficient. Not saying there aren't problems with economics, cough cough DSGE cough, but I don't think assuming efficiency is one of them.

This joke (despite being funny) is somewhat misleading of actual economic theory for 3 reasons: 1) market efficiency occurs over the long-term, 2) shocks (of the exogenous and endogenous kind) tend to reset the point at which markets clear, 3) both 1 (duration) & 2 (frequency) are far greater in magnitude under anything like real world conditions. Still more so within the tech industry.

Ya, economics would tell you that it very well may be a hundred dollar bill and you should take advantage. But it would also tell you that you probably aren't going to keep finding them and it won't be sustainable to go looking for them.

Agreed, market efficiency assumes buyers are looking for the global maxima rather than settling for a local maxima.

Every mirage is an opportunity, either to succeed or to become wiser for the price of being wrong.

Surprised no-one mentioned this yet, but it's quite possible (probable even) that it's a fake, an ad designed to waste your time by getting you to pick it up. A very common in some parts of the world, which makes walking past the rational thing to do.

Where in the world are guerrilla ads disguised as money so commonplace that one simply ignores them? I have never seen such a thing in my life.

New Jersey.

well I've never found a hundred dollar bill on the ground in real life, have you?

I have found (and returned) several phones worth considerably more.

I used to do my morning runs in a park area which was frequently used at night for illegal partying. So every once in a while I would find wallets with IDs, passports and a phone. Naive and honest as I was, I always took these to a police station that was nearby. I stopped doing this when the police started to (informally) accuse of me of having stolen these items, like the stories of the firefighter that would start fires by himself. I changed my running route so it wouldn't take me near the partying spots anymore.

IIRC someone proved that if markets are efficient, the P=NP.

That convinces me that P!=NP, heheh.

>>Two economists are walking down the street and pass by a hundred dollar bill without picking it up.

I can't help but notice that the joke rests on an impossible premise that they didn't pick it up on first notice.

Whoosh? That's the joke.

They are so convinced in their theories, that a real world discontinuity in them is instead, seen as impossible.

EG, Why would they pick up what clearly (to them) cannot exist?

but to me it requires the economists to be so stupid to not consider the possibility that they might be indeed the first people who observe it after it has been lost..

That's the joke. Ignoring reality, empirical evidence, due to theory.

Ok, Thank you for your patience :)

Wow.... That this had to be explained.

That joke is wildly inaccurate.

The $100 is vaguely seen in the middle of the street during traffic. Is it actually $100? Maybe it's just a dollar bill. And are you good enough to grab it without getting hit?

Maybe it's true if you come from a rich background and have family wealth to fall back on, which I suspect is where most of these people are coming from.

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