Adaptive Coding is the property of the brain to adjust its response to statistical properties of the environment. Its effect is an improved discrimination among signals under the constraints on the dynamic range of its response. It can thus be considered the neural correspondent of Rational Attention, which models how a rational decisionmaker allocates attention among different informative signals. There is strong evidence of existence of widespread adaptive coding. Adaptive coding introduces a dependence of choice from the environment which is not observed in behavior. We discuss potential solutions and propose Hebbian learning as a potentially satisfactory answer.

Gender gaps may be observed in a variety of economic and social environments. One of the possible determining factors is that men are more competitive than women and so, when the competitiveness of the environment increases, the performance of men increases relative to that of women. We test this hypothesis in a field study conducted with 9-year old children, running on a track. They first run alone and then in pairs over a short distance with different gender composition of the pairs. The results support the hypothesis that performance in competition varies according to gender. When children ran alone, there was no difference in performance. In competition boys, but not girls, improved their performance. This finding relates to the discussion regarding single sex schools: the outcomes of examinations in a mixed sex school can show a gender gap in favor of boys, even when this gap does not reflect actual abilities. Girls who are as talented as boys will end up performing worse just because they are not as competitive, and will not achieve as high scores in examinations as boys.

We relate two main representations of the cost of acquiring information: a cost that depends on the experiment performed, as in statistical decision theory, and a cost that depends on the distribution of posterior beliefs, as in applications of rational inattention. We show that in many cases of interest, posterior-based costs are inconsistent with a primitive model of costly experimentation. The inconsistency is at the core of known limits to the application of rational inattention in games and, more broadly, in equilibrium analyses where beliefs are endogenous; we show that an experiment-based approach helps to understand and overcome these difficulties.

People who are members of a group and identify with it behave differently from people who perceive themselves as isolated individuals. This paper shows that group membership affects preferences over outcomes, and saliency of the group affects the perception of the environment. We manipulate the saliency of group membership by letting a player's own group watch as a passive audience as decisions are made, and/or by making part of the payoff common for members of the group. In contrast to the minimal-group paradigm, minimal groups alone do not affect behavior in our strategic environments. However, salient group membership significantly increases the aggressive stance of the hosts (people who have their group members in the audience), and tends to reduce that of the guests.