Making Information More Valuable
Pith reviewed 2026-05-24 10:46 UTC · model grok-4.3
The pith
A change makes information more valuable exactly when the agent's reduced-form payoff becomes more convex in her beliefs.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We prove that information becomes more valuable if and only if the agent's reduced-form payoff in her belief becomes more convex. When the transformation corresponds to the addition of an action, the requisite increase in convexity occurs if and only if a simple geometric condition holds, which extends in a natural way to the addition of multiple actions. We apply these findings to two scenarios: a monopolistic screening problem in which the good is information and delegation with information acquisition.
What carries the argument
The reduced-form payoff function that maps the agent's posterior belief to her expected payoff, with its degree of convexity determining the value of information.
Load-bearing premise
The agent's decision problem can be represented by a payoff that is a function solely of her posterior belief.
What would settle it
An example of a transformation of a decision problem that increases the value of information without making the reduced-form payoff more convex.
read the original abstract
We study what changes to an agent's decision problem increase her value for information. We prove that information becomes more valuable if and only if the agent's reduced-form payoff in her belief becomes more convex. When the transformation corresponds to the addition of an action, the requisite increase in convexity occurs if and only if a simple geometric condition holds, which extends in a natural way to the addition of multiple actions. We apply these findings to two scenarios: a monopolistic screening problem in which the good is information and delegation with information acquisition.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proves that a transformation of an agent's decision problem increases the value of information if and only if the agent's reduced-form payoff function v(μ) over posterior beliefs μ becomes more convex. When the transformation is the addition of an action (or multiple actions), the required increase in convexity holds if and only if a stated geometric condition on the new action's payoffs is satisfied. The result is applied to a monopolistic screening problem in which the good sold is information and to a delegation setting with endogenous information acquisition.
Significance. If the central if-and-only-if characterization holds, the paper supplies a direct, decision-theoretic criterion for ranking the value of information across decision problems that builds on the standard representation v(μ) = max_a ∫ u(a, θ) dμ(θ) and the fact that any mean-preserving spread of posteriors is attainable. The geometric condition for action addition and the two applications to screening and delegation are concrete strengths. The result is parameter-free and derived from primitives without ad-hoc assumptions.
minor comments (3)
- [§2] §2 (or wherever the reduced-form payoff is first defined): explicitly state the domain of v(μ) and confirm that the belief simplex remains unchanged after the transformation, as this is required for the convex-order comparison to be well-defined.
- [§3] The geometric condition for adding an action (likely in §3) would benefit from a diagram or explicit coordinate example to illustrate the half-space or supporting-hyperplane interpretation.
- [Application 1] In the screening application, clarify whether the monopolist's reduced-form payoff is computed before or after the buyer acquires information, to avoid ambiguity in the convexity comparison.
Simulated Author's Rebuttal
We thank the referee for their supportive summary and recommendation of minor revision. No major comments were raised in the report.
Circularity Check
No significant circularity
full rationale
The paper's central claim is a standard if-and-only-if characterization: a transformation increases the value of information precisely when it increases the convexity of the reduced-form value function v(μ) = max_a ∫ u(a, θ) dμ(θ). This follows directly from the definition of the value of an information structure as E[v(μ)] − v(μ0) and the fact that any mean-preserving spread of posteriors is attainable; the equivalence to convex order is a direct consequence of these primitives and holds after any well-defined transformation of the decision problem. No load-bearing step reduces to a fitted parameter, self-citation chain, or definitional renaming. The derivation is self-contained against external decision-theoretic benchmarks.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption The agent's payoff admits a reduced-form representation as a function of her posterior belief only.
discussion (0)
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