Economic activity in its different manifestations--production, exchange, consumption and, particularly, information on quantities and prices--generates and transfers energy. As a result, we can apply to it the basic laws of thermodynamics. These laws are applicable within a system, i.e., in a country or between systems and countries. To these systems we can apply the thermodynamic principles. In order to work with these concepts, we must first define what a system, in this case an economic system, is and then explain what we mean by a closed or open system. Given that entropy is intimately connected to the level of disorder within a system and, thus, with its information, this multiple vector connects the systems internally and externally.