以下是引用xianzs在2005-9-3 9:48:31的发言: 没有这个假设。
六楼的朋友的回答有问题。在本质上,NPV方法与IRR方法是一致的,也就是说,NPV与IRR的评判结果是一致的,是一个方程等式的不同解释。
The only thing your need to know is what the question is. The thing he asked is what the underlying assumption in this model not what the result is from these two methods. What you said is true but doesn't answer the question.
Here are some definitions from my previous papers.
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Define NPV and IRR.
· NPV: Net present value is a capital-budgeting concept defined as the present value of the project’s annual net cash flows less the project’s initial outlay. It can be obtained by discounting the all cash flows on the project, including the initial investment at the appropriate hurdle rate.
· Decision Rule: Accept if NPV > 0
· Preference: if a business has substantial funds on hand, access to capital, limited surplus value projects, and more certainty on its project cash flow, it is much more likely to use NPV
· IRR: Internal rate of return is a capital-budgeting technique that reflects the rete of return a project earns. This internal rate of return is the discount rate that sets the net present value equal to zero. The IRR rule assumes that intermediate cash flows on the project get reinvested at the IRR. The implication of this assumption is that the firm has an infinite stream of projects yielding similar IRR
· Decision Rule: Accept if IRR > hurdle rate
· Preference: if a business has limited access to capital, has a stream of surplus value projects and faces more uncertainty in its project cash flows, it is much more likely to use IRR.
Define MIRR
Modified internal rate of return (MIRR) is the rate of return which equates the initial investment with a project’s terminal value, where the terminal value is the future value of the cash inflows compounded at the required rate of return (the opportunity cost of capital).
Benefit:
It provides a measurement of project return in percentage.
It avoids the upward bias as it assumes that any cash flows from the project will be reinvested at cost of capital, which is more appropriate in real world.
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下面这两个是网上的信息. 你可以查查. 说得再清楚不过了.
Damodaran, http://pages.stern.nyu.edu/~adamodar/pdfiles/ovhds/ch5.pdf, P198
Reinhart: http://www.departments.bucknell.edu/management/apfa/Dundee%20Papers/37Reinhart.pdf, P3