PURPOSE : A method for explaining the failure of an economy system which is generated from an unjust gain is provided to enable a user to easily understand the economy growth and stable society.CONSTITUTION : An interest rate increases as much as productivity through an economy system in which an unjust gain is not generated. Through economy system, the price of the real estate increases as much as the increase of the productivity. Through the economy system, the price of the building increases by the increase of rent and the decrease of vacancy rate. Through the economy system, the stock price index of the stocks increases.COPYRIGHT KIPO 2012