So markets can only be (perfectly) efficient or competitive, not both at the same time. Largely theoretical but it tracks common sense!

The title on this HN submission is just wrong. Click on the link and find out.

	▲	seizethecheese an hour ago \| parent \| next [-]
		The title is wrong but you’re also wrong. Read the abstract of the paper. Here’s the relevant section: > Combined with Maymin (2011), who proved that market efficiency requires P = NP, this yields a fundamental impossibility: markets can be informationally efficient or competitive, but not both.
	▲	abejfehr 2 hours ago \| parent \| prev [-]
		isn't that what they're saying with "not both at the same time"? the papers both have opposite signs, one has != and the other has =