Information Design

Information design is the study of how the structure of information available to strategic agents influences the outcomes of their interactions. Rather than treating information as exogenous — something that agents simply have or do not have — information design treats it as a choice variable, asking what information structure a designer should provide to achieve a desired outcome.

The field unifies Bayesian persuasion, correlated equilibrium, and mechanism design under a common framework. In each case, the designer does not directly control actions but instead controls the information environment within which agents act. The mathematical tools — Bayesian updating, incentive compatibility, revelation principle — are shared across all three domains.

What distinguishes information design from classical mechanism design is its focus on information structures rather than allocation rules. A mechanism designer asks "who gets what?"; an information designer asks "who knows what?" The answer to the second question often determines the answer to the first. See strategic information transmission for the dynamics of information revelation when commitment is not possible.