Bounded and ecological rationality: A research program

What is rational judgement and decision making? One of the classical answer s to this question has been that judgements and decisions are rational if t hey conform to the rules of various normative systems such as the probabili ty theory or expected utility theory. Embedded within this conception of ra tionality is the fiction that rational agents have unlimited time, knowledg e, and computational resources for making decisions. However, humans only h ave limited resources, which is why Herbert Simon conceptualized human rati onality as "bounded." Boundedly rational decision making does not by any me ans entail poor performance. We provide examples of computationally simple heuristics that require little information, yet lead to surprisingly accura te judgments. The key to their success is ecological rationality, that is, their adaptation to the information structure of the environments in which they work.