calculating profitability 6. Clarity. Plan should be clearly expresses the organization's goals and tasks, clearly expresses the resources necessary to achieve goals and taken by the procedures, methods and means, explicitly expresses the managers at all levels in the rights and duties in the process of execution plan. In theoretical economics, investment means buying (and therefore producing) capital goods - not being consumed but being used in future production. Examples include building railroads, or factories, cleaning the land, or allowing yourself to go to college. Strictly speaking, investment in formula GDP= C + I + G + NX is also part of gross domestic product. In that respect, the function of investment is divided into non-residential investments (such as factories, machinery, etc.) and residential investment (new homes). The correlation between I = (Y, I) is known to have a close relationship with income and interest rates. Higher incomes would boost higher investment, but higher interest rates would discourage investment because it would be more expensive to borrow. Even if companies choose to use their own funds to invest, interest rates represent the opportunity cost of investing in those funds rather than the interest that will lend out. Because economists understand earnings as actual material wealth increase, accounting experts think the output value of more than the difference between the input value is profits, there is a contradiction and two kinds of income concept. The specific performance is: Fold development The market can indeed be described as a laissez-faire pricing mechanism. However, this price mechanism does not operate in a vacuum, and does not work effectively in any social system. The basic premise of the efficient operation of the price mechanism is the implicit assumption of Smith: to recognize individual "lusts" and to clear and protect individual property rights. Clear and guaranteed personal property is the basic premise of market existence. It is necessary to recognize the personal "lusts" and to ensure that individual property rights are supported by the corresponding institutions, which are not in our society. (3) lorries: vehicles mainly used for transporting goods.