Previously circulated as “Information Overload and Confirmation Bias”. With Lorenz Götte and Hua-Jing Han. Accepted at Games and Economic Behavior, July 2026.
Abstract We show that stronger memory overload results in a disproportionately greater under-reaction to belief-challenging information compared to belief-confirming information. In an experiment, we keep constant the information received by subjects but vary the difficulty of memorizing the signals. In the treatment condition, the preceding signal disappears as the next signal appears. In the control condition, the preceding signal remains visible. There is stronger memory overload in the treatment than in the control condition. We find that in the treatment condition, subjects under-react when they receive belief-challenging information but not when they receive belief-confirming information. Further analysis supports the mechanism in which it is more cognitively taxing to memorize belief-confirming than belief-challenging signals. However, it does not support the mechanism in which subjects have a fixed amount of cognitive resources to allocate to different signals. Our results caution against information campaigns that ignore the role of cognitive load and attention.
