Research Article JME 2019,2:9 On one criterion for the permanent economy development A new method of investigation the equilibrium state of the economy is proposed. The classification of the equilibrium states is given. The basic principle of equilibrium the economy system to its environment is formulated. It is used to obtain the money circulation equation. On this basis the notion of the permanent economic development is defined. The analysis of the economy of four contries is given. The principe of adequacy of currency exchange and inflation rates to the factors that their determine is proposed.

We have elaborated a new method to study international trade based on the theory of economic equilibrium. Here we give developed algorithms to construct equilibrium states. Within the framework of the theory of economic equilibrium, we suggested a mechanism explaining the recession phenomenon by the exchange mechanism breakdown. For this purpose, we introduced the recession level parameter. The paper gives our study of goods exchange nature between countries of the G20. It turned out that in each studied year, the trade between the G20 countries was not in equilibrium. The equilibrium state of trade between the G20 countries was highly degenerated and far from ideal equilibrium. Also, we have calculated the recession level parameter for each equilibrium state and it showed that the international currency was strengthening during 2016-2019.