arrow-information-paradox

# Arrow's Information Paradox ## Overview You have something valuable to sell — a technology, a formula, a method, a dataset, a research result. A buyer wants to know what it is worth before paying. But to judge its worth, they must know what it *is*. And the moment they know what it is, they have already received it — for free. You have nothing left to sell. This is **Arrow's information paradox**, stated by Nobel laureate Kenneth J. Arrow in 1962: > "there is a fundamental paradox in the determination of demand for information; its value for the purchaser is not known until he knows the information, but then he has in effect acquired it without cost." > — Kenneth J. Arrow (1962), *Economic Welfare and the Allocation of Resources for Invention* Arrow traced the paradox to three problematic properties that make information behave unlike an ordinary good. It is **indivisible** — you cannot sell a fractional peek that conveys proportional value; the useful unit is often the whole thing. It is **inappropriable** — once disclosed it is non-excludable and non-rivalrous; the buyer's use does not diminish yours, and you cannot easily stop them (or others) from using it without paying. And it is subject to **uncertainty** — neither party knows in advance what the information will be worth, and the seller cannot credibly resolve that uncertainty for the buyer without dissolving the sale. The whole discipline of this skill is the executable move that follows: *choose the mechanism ...