This paper models how imperfect memory affects the optimal continuity of policies. We examine the choices of a player (individual or firm) who observes previous actions but cannot remember the rationale for these actions. In a stable environment, the player optimally responds to memory loss with excess inertia, defined as a higher probability of following old policies than would occur under full recall. In a volatile environment, the player can exhibit excess impulsiveness (i.e., be more prone to follow new information signals). The model provides a memory-loss explanation for some documented psychological biases, implies that inertia and organizational routines should be more important in stable environments than in volatile ones, and provides other empirical implications relating memory and environmental variables to the continuity of decisions.
This paper explains why seemingly irrational overconfident behavior can persist. Information aggregation is poor in groups in which most individuals herd. By ignoring the herd, the actions of overconfident individuals (“entrepreneurs”) convey their private information. However, entrepreneurs make mistakes and thus die more frequently. The socially optimal proportion of entrepreneurs trades off the positive information externality against high attrition rates of entrepreneurs, and depends on the size of the group, on the degree of overconfidence, and on the accuracy of individuals’ private information. The stationary distribution trades off the fitness of the group against the fitness of overconfident individuals.