In this bachelor thesis I’ve tried to show what are the most important factors influencing behavior during an institutional change. One of the most important things was to explain why there is a strong persistence in behavior and why path dependency in institutions emerges. In the first chapter I discuss the standard microeconomic approach to behavior known as homo oeconomicus, in the second one an alternative approach based on routines and subjective mental models is presented. With this “evolutionary” approach I’ve explained institutions as a consequence of shared mental models. Then, in the third chapter, I discussed implications of this model for institutional change with analogies of technological change and with contributions of social psychology and cultural anthropology as well.