This paper shows that price rigidity evolves in an economy populated by imperfectly rational agents who experiment with alternative rules of thumb. In the model, firms must set their prices in face of aggregate demand shocks. Their payoff depends on the level of aggregate demand, as well as on...

The weak rationality principle is not an empirical statement but a heuristic rule of how to proceed in social sciences. It is a necessary ingredient of any ‘understanding’ social science in the Weberian sense. In this paper, first this principle and its role in economic theorizing is...