According to this model, the interest rate decision depends on the supply of savings and investment needs, money supply, money demand, four factors, cause a change in the saving investment, money supply and demand factors will affect the level of interest rates. This theory is characterized by general equilibrium analysis. The important thing to keep in mind when being sued by plastic card company or junk debt buyers is when they do not have proof that will otherwise prove how the debt is yours, they do not have a case. For junk debt buyers, you are in luck since these agencies don't have the required documents that might prove you possess the debt, like a signed contract between you and the original creditor, because they documents are never released with the original creditor. The euro zone's landmark buildings are seen at the headquarters of the European central bank (ECB) in Frankfurt The accounting income maintains the financial capital preservation, namely, the monetary value that only requires the owner to invest is not eroded, the enterprise income exceeds the input value part is the accounting income. Accounting focuses on reporting financial results. The economic benefits insist on physical capital preservation, which can only be confirmed when the actual production capacity of the owner is saved. It is believed that only by maintaining the actual production capacity of the enterprise can the enterprise reproduce smoothly. Physical capital preservation is more meaningful than the income of financial capital preservation, but it is difficult to measure. 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.