Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Markets are competitive if and only if P != NP

arxiv.org

Post reply on HN
Print view View original

61–70 of 176 posts

Re: Markets are competitive if and only if P != NP

#61

Post by wellbehaved »

"Third, I propose computational antitrust: the principle that market complexity itself is a competitive safeguard, and that regulators should consider computational difficulty as a design parameter."

This "should" is doing a lot of work here. The paper is mainly about a game-theoretic model allegedly corresponding to real markets, but establishing what regulators ought to do requires far more rationale than mere math. It requires a bridge from "is" to "ought." It reminds me of Hume's warning about this kind of non-sequitur:

"In every system of morality, which I have hitherto met with, I have always remarked, that the author proceeds for some time in the ordinary ways of reasoning, ... ; when all of a sudden I am surprised to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is however, of the last consequence."

Re: Markets are competitive if and only if P != NP

#62

Post by fluoridation »

ladberg wrote: post #59
brunoborges wrote: post #52

It's time to forbid bots and HFT. Want to buy/sell a stock? Humans need to manually submit in the system.

Why? Don't you prefer getting better prices when you want to go buy a stock?

I prefer a better price delta between buy and sell, which is blind to price hikes across the board.

Re: Markets are competitive if and only if P != NP

#63

Post by marcosdumay »

iwontberude wrote: post #43
marcosdumay wrote: post #23

Earlier quoted context omitted.

Yet neither paper seems to eliminate the case of markets being neither. So both titles are incorrect.

Yeah using time complexity for computers to describe markets is simultaneously awesome and stupid.

The idea that markets are an optimizing algorithm is kinda old already, and well established.

Both papers seem to be jokes about it, based on complete caricatures of competitiveness and efficiency. It's kinda like a recent paper that was posted here proving "general intelligence" impossible while ignoring that humans exist.

Re: Markets are competitive if and only if P != NP

#64

Post by magicalhippo »

cwmoore wrote: post #8
cs702 wrote: post #4

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.

So it pulls exclamation marks. . .angle brackets maybe? “=“ “!=“

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

Most filters are to avoid sensational titles, AFAIK.

Re: Markets are competitive if and only if P != NP

#65

Post by ladberg »

fluoridation wrote: post #62
ladberg wrote: post #59

Earlier quoted context omitted.

Why? Don't you prefer getting better prices when you want to go buy a stock?

I prefer a better price delta between buy and sell, which is blind to price hikes across the board.

That's exactly what "better prices" means...

Re: Markets are competitive if and only if P != NP

#66

Post by consensus1 »

derektank wrote: post #32
xxpor wrote: post #2

The actual paper's title is "Markets are competitive if and only if P != NP" Seems that HN's auto-headline rewriting in this case has made a critical error :) >Artificial intelligence, by expanding firms' computational capabilities, is pushing markets from the competitive regime toward the collusive regime, explaining the empirical emergence of algorithmic collusion without explicit coordination. I have to dig more i…

Yeah, the most obvious recent example of this is RealPage’s YieldStar product. It advised property managers on what they should set their rental rates to, and allegedly established a cartel in which RealPage’s customers coordinated in pricing their units. YieldStar was technically an “AI” product, but I don’t really think the computational abilities were what enabled the collusion. RealPage’s employees (according to…

I was always skeptical of the algorithmic cartel argument in that case. Turns out it was just a regular cartel all along.

Re: Markets are competitive if and only if P != NP

#67

Post by IsTom »

jfengel wrote: post #46
BoardsOfCanada wrote: post #31

A lot of things are only true if P != NP but says nothing about P being within epsilon of NP.

Not quite sure what you're suggesting here; perhaps it's satire? If P!=NP then it is arbitrarily smaller, for the same reason that e^x > Cx^N for any constants C and N, as long as x grows big enough. There is no epsilon in that can overcome that, no matter how big you make it, because x will eventually dominate the equation. There are a lot of cases where pragmatically x remains small enough that it doesn't matter, a…

In case P /= NP the gap doesn't necessarily have to be exponential, just superpolynomial (e.g. n^loglogn).

Re: Markets are competitive if and only if P != NP

#70

Post by estebarb »

This is interesting. Adam Smith said "People of the same trade seldom meet together, even for merriment and diversion, but the conversation ends in a conspiracy against the public, or in some contrivance to raise prices."

The annoying part is that, as the same Adam Smith says, regulating industries would end up enforcing such assemblies, reinforcing the problem... after all, industries can share information via the market itself...

And proposed solutions end up being controversial: employees ownership, open source, paying taxes over stocks ownership... or just hoping that colluders will be broken by a randomly ocurring incumbent...

Post reply on HN