We study when equilibrium prices can aggregate information in an auction market with a large population of traders. Our main result identifies a property of information—the betweenness property that is both necessary and sufficient for information aggregation. The characterization provides...

We study when equilibrium prices can aggregate information in an auction market with a large population of traders. Our main result identifies a property of information---the betweenness property---that is both necessary and sufficient for information aggregation. The characterization provides...