"An economic system is a set of dependent, interconnected economic relationships which, precisely because they are interconnected, arise more or less contemporaneously and disappear more or less contemporaneously, giving way to other relationships. The empirical dating of their emergence and dissolution enables us to fix the limits of a specific economic system in time. To construct the theory of a determinate economic system means to establish (always empirically) the fullest possible totality of dependent relationships present within the system, and to explain the connections between these relationships."

— Wiltold Kula