[cs702]

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.

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

[ajkjk]

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

[throwaway27448]

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.

[peder]

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.

[tsimionescu]

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).

[BobaFloutist]

I always thought of supply and demand as more defining a limit that the price approaches as the number of transactions and the size of the market approach infinity, barring structural obstacles or persistent information asymmetry to prevent it than as something that was supposed to happen immediately on any given transaction.

[bryanlarsen]

Businesses generally follow the rule "price is set to whatever the market will bear". Which is just an indirect way of setting price by supply and demand.

[wrqvrwvq]

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.

[tsimionescu]

> If cost plus is not an attractive price, it won't sell, because the demand is not there.

Sure, but that only sets a cap. The market might bear twice the initial price, but few businesses actually take the time in practice to explore things at this level

[wrqvrwvq]

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.

[dash2]

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.

[throwaway27448]

Well yes, market forces as theorized are the very premise we've structured our entire economy around. Or, more bluntly, the desire to purely encapsulate political-economic power in capital. How else could an economic process operate without being attacked by the state? But this is also why our market behaves so irrationally—these concepts have very obvious predictive limits that investors are struggling to grapple with and our politicians (and largely our electorate tbf) have blind faith in

[WarmWash]

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

[dinfinity]

To be fair, macroeconomics can hardly be called science, though. It is incredibly hard to falsify a lot of the theories given the lack of possibilities for experimentation. It is far closer to philosophy than to any of the even remotely hard sciences.

Nothing to do with ideology, but with the nature of the field. Take epidemiological research in the areas of food and medicine: incredibly hard and expensive to get right and even then with often tenuous results. Now try doing that with ridiculously heterogeneous nations influenced by potentially almost everything on the planet.

It's a small miracle that economists manage to get some useful insights out of the data, but we should definitely be aware of how weakly most of them are supported (don't start talking about "error bars" with economists).

[WorldMaker]

An argument of the last couple of decades is that videogames have built incredible labs for macroeconomic experimentation. So far mostly what we learn are failure cases (mudflation, being such a big learning from videogames that the term itself is named after a type of them), but we are learning things (some of them exploitative, but that's a different ethical question).

[stymaar]

In fact that there's both a liberal and conservative economics ideology, and what could form a scientific discipline in between is unfortunately cornered and sorely lacking visibility.

[throwaway27448]

The distinction between liberal and conservative political labeling in america is entirely cultural. There is precisely zero ideological, ie political-economic, difference. It's just culture wars all the way down while we get pickpocketed together.

[throwaway27448]

I think exactly the opposite: adherence to market economics, even to the extent of calling it a science, is what defines a liberal. In this sense conservatives are just angry liberals.

Tbf, most americans just sort of skate along on vibes and don't have many concrete values or material understanding of our society at all, regardless of how they identify.

Cf any argument over rent control: people either want it out of some sort of justice for inhumanely priced rents, or people bought into some kind of idea that it doesn't work because some think tank they put faith in pushed that messaging. Few people actually study the literally thousands of ways that almost every other society manages to house their population more effectively. It's all just vibes.

[WorldMaker]

I've been picking up a different feeling that economics is sort of in a pre-calculus moment that conservatives/libertarians and liberals/progressives have sort of been building two different sciences of economics and are missing the "calculus" to reunite them (or at least choose the winner between them).

I mention calculus specifically because it does feel like more of the progressive movements in economics are focused on rate of change rather than point in time. I personally often tend to get into electrical circuit analogies that current/resistance/impedance are more useful than steady state voltage. I find I especially bring these metaphors up a lot when discussing cryptocurrencies (and why I distrust them: inflation/deflation is the wrong axis, in my opinion, some inflation is a useful sign of "impedance" in the circuit, the trick to a healthy economy is not "deflationary" [most of real world history states that the deflationary economies are the worst to live in] but carefully managing the rate of change of inflation).

That progressive science of economics is happening, slowly (this paper seems relevant), but so much of conservative discussions get trapped in (misreads of) Adam Smith still. From a progressive point of view it does seem easy to dismiss conservative views of economics as bunk pseudoscience if they begin and nearly always end with Adam Smith, ignore some of Adam Smith's own warnings (for instance, relevant to above conversation: Adam Smith was also often the first to admit that the "free market" is an ideal/a model and unlikely to ever be a reality because humans are messy and ultimately irrational as individuals), and also ignore centuries worth of work since then, especially a lot of the "pre-calculus" stuff.

[casey2]

The vast majority of cash transactions are fired by a computer model so the implication are significant. It goes a long way towards explaining why increasingly financialized countries aren't experiencing noticeable real world improvement while also becoming increasingly extractive.

[wuschel]

Hmm. I am not so sure about that statement. There are many models at play in the market, not one model. What mechanistic patterns are driving those models that are falsified by this paper and lead to the outcome of increasingly extractive/stagnating economies?

[imtringued]

Neoclassical economics is based around the idea that markets are 100% efficient. If they are only 99% efficient the whole thing falls apart, because the standard defense of neoclassicals against exponentially growing defects in the economy is that they never happen in the first place. The moment you permit a 1% defect rate, the cascade starts and it is only a matter of time for things to go wrong.

[throwawayqqq11]

Reminds me of the spiraling wealth gap as an outcome of markets.

[baq]

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

[mcdeltat]

No bro you don't understand bro, supply and demand maths said capitalism is the only way forward bro and give me money now

[cwmoore]

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

    “=“ <> “!=“

[magicalhippo]

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

Most filters are to avoid sensational titles, AFAIK.

[kleiba2]

UTF8 to the rescue: ≠

[dvh]

Fun fact, pascal uses <> for inequality

[adrianmonk]

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]

Sql too

[hughw]

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

[kps]

You had lower case? In my day...

[nok22kon]

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

[falcor84]

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.

[dash2]

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

[HPsquared]

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

[pixl97]

The utility monster has decided that numbers are more useful than products usable by humans.

[fc417fc802]

"Ahkchually the paperclip maximizer isn't maximizing [human] utility, just a dumb metric" isn't a particularly useful observation to make in the context of the world being gradually consumed by an army of nanobots.

[HPsquared]

I'm thinking of an earlier time when computers ran on "facts and logic" and you could probably stop the machine by giving it a logical conundrum. Vibes-based systems are a lot more resistant to this, but can still be distracted.