gross profit margin formula uk In economic terms, the benefits of holding any two currencies should be equal in the equilibrium of the foreign exchange market, which is: Ri=Rj (interest rate parity). Here, R stands for yield, and I and j represent currencies of different countries. If the benefits of holding two currencies are unequal, you will have A arbitrage: buy A kind of foreign exchange and sell B foreign exchange. The marxist theory holds that the profit under the capitalist system is the transformation form or phenomenon of surplus value, which manifests as the balance of commodity value over cost price. That is, the total amount of the proceeds of the sale of the goods by the capitalist exceeds the balance of his prepaid capital. Profit from a home variable capital purchase Labour created in the process of production of surplus value, also is the surplus labor hiring workers create surplus value, can change capital proliferation. But it is manifested in the phenomenon as the capital increase of capital of capital of capital. Stopping trading is an important part of the plan. It can be seen that shares and shares are the relationship between form and content and cannot be confused. Famous British economist hicks and others argue that the above theory did not consider the factor of income, and therefore unable to determine the level of interest rates, in 1937, and puts forward the is-lm model on the basis of general equilibrium theory. It establishes a theory of interest rates and income at the same time that the four factors of savings and investment, money supply and monetary demand interact. Lay the foundation disappointing because of the best performance of the global economy since the financial crisis.