Very interesting. The author claims to have proved that markets can be informationally efficient or competitive, but not both. The implications for policy and regulation are significant.

The author looks credible:

https://philipmaymin.com/about-philip

Thank you for sharing this on HN.

To the mods: The title needs to be edited to replace the equal sign with not-equal.

▲ ajkjk 2 hours ago | parent | next [-]

The implications are not significant..? the real world is messy enough that this will not ever apply.

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throwaway27448 an hour ago | parent | next [-]

The fact that free markets don't exist, and that supply and demand is not a natural law that implies efficient markets has never stopped people acting like both are true and stuffing fingers in their ears.

But, both free markets and supply/demand are useful enough concepts to talk loosely about processes to understand the interest that I'll enjoy digging into this.

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peder an hour ago | parent [-]

They're not just useful concepts tho, they're how every business operates, and the concepts cover the vast majority of situations.

The behavioral economics/Freakonomics thing was like "Hey, here's this thing that might if you squint real hard fall outside of efficient market theory" and then for a decade people took that to mean that that the base concepts were worthless, which was a severe overcorrection from people that didn't understand economics.

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wrqvrwvq 24 minutes ago | parent | next [-]

Knowledge accumulation seems to have cyclical patterns where general observations are condensed into "laws", and common wisdom is to treat these as unassailable truths. As exceptions and contradictions are found, the popular wisdom is to entirely dismiss the overwhelming universal conformity with the earlier principles because it sounds smart to common people. A lot of normal people see the basic problems with most methodological maxims but are led to believe that the maxim is truth. It takes a podcaster with a "study" to then "debunk" the "myth" they were yesterday defending as unimpeachable. People are generally not well informed enough to know anything and the podcaster class is the worst imaginable vector for knowledge dissemination or popularization. Just clickbait garbage monkeys with foreign money and vicious antisocial tendencies.

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tsimionescu 32 minutes ago | parent | prev | next [-]

The vast majority of real world businesses create prices based on cost plus systems, not on supply/demand, which are generally impossible to measure directly. Another good chunk of smaller businesses simply copy the prices of larger businesses, at least in b2c markets. Sure, if their goods are not selling, they might reduce price, but they might try other tactics as well (marketing, targeted discounts, etc).

	▲	wrqvrwvq 20 minutes ago \| parent [-]
		these "other tactics" are just attempts at increasing demand. Cost plus is how many business set prices but that is entirely separate from what the market decides. If cost plus is not an attractive price, it won't sell, because the demand is not there.

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dash2 27 minutes ago | parent | prev | next [-]

There are many ways that free and competitive markets can fail other than behavioural economics! Monopoly, informational asymmetry, externalities… All of these are plausibly pervasive.

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WarmWash 16 minutes ago | parent | prev [-]

Economics is one of the scientific sore spots for liberal ideology. If you are liberal and mostly swim in liberal circles, you probably believe that economics is mostly bunk pseudoscience. Akin to conservatives and climate change

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baq 2 hours ago | parent | prev [-]

the abstract itself explains why there is a problem even if the real world is messy; markets are a social construct

▲ cwmoore 2 hours ago | parent | prev | next [-]

So it pulls exclamation marks. . .angle brackets maybe?

    “=“ <> “!=“

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magicalhippo an hour ago | parent | next [-]

It removes a lot of things when posting, but submitter can edit and put them back.

Most filters are to avoid sensational titles, AFAIK.

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kleiba2 2 hours ago | parent | prev [-]

UTF8 to the rescue: ≠

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dvh an hour ago | parent [-]

Fun fact, pascal uses <> for inequality

	▲	adrianmonk 15 minutes ago \| parent \| next [-]
		So does BASIC. It might even be the first, although it's hard to be sure. BASIC[1] came out in 1964, and Pascal[2] came out in 1970. --- [1] https://en.wikipedia.org/wiki/Dartmouth_BASIC [2] https://en.wikipedia.org/wiki/Pascal_(programming_language)
	▲	dgellow an hour ago \| parent \| prev [-]
		Sql too

▲ hughw 2 hours ago | parent | prev | next [-]

For the older among us, that's .ne.

	▲	kps an hour ago \| parent [-]
		You had lower case? In my day...

▲ nok22kon 2 hours ago | parent | prev [-]

assuming the typical "spherical market in a vacuum where the agents are maximally rational non-biological utility maximizers"

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falcor84 an hour ago | parent [-]

Well, for better or worse, markets are becoming increasingly dominated by "non-biological utility maximizers" - mostly hft bots, but now also llm-based reasoning agents.

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dash2 18 minutes ago | parent | next [-]

Actually there’s a literature on whether llms have the standard cognitive biases, via cultural inheritance….

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HPsquared 26 minutes ago | parent | prev [-]

They're not necessarily maximising utility, just the number on the screen.

	▲	pixl97 2 minutes ago \| parent [-]
		The utility monster has decided that numbers are more useful than products usable by humans.