摘要
外部收益率指标一直为国内工程经济学家所青睐,但美国工程经济学家基于现金流不能依据双重评价标准予以折现,而否定这一指标。应用反证法,并结合互斥方案净现值曲线可能相交产生菲什尔点是导致外部收益率指标失效的原理,放松净现金流折现的假设条件,模拟计算两条外部收益率曲线,从而产生一个与菲什尔点相类似的交叉点,而这个类菲什尔点的数值并不等于菲什尔点的数值,从而导致用外部收益率对互斥方案选优将产生新的混乱。据此可以判定外部收益率指标建构的不合理性。具体结论如下:(1)ERR指标与IRR指标相比,具有唯一解。这是它相对IRR而言唯一的优点。(2)计算ERR一般也需要迭代试算并利用插值法。与IRR相比,计算并不简便。(3)ERR在互斥方案选优时无法直接应用,远逊于NPV;而且会造成类菲什点与菲什尔点的不同,导致选择的混乱。故建议在评价指标体系中予以剔除。
External rate of return(ERR)has always been favored by Chinese engineering economists, but American engineering economists deny it because they think cash flow can 't be discounted on the basis of double evaluation standard. In this paper, we use reduction to absurdity the principle that the Fisher point produced by the possible intersection of the net present value of the exclusive scheme curve is the ultimate reason for the ineffectiveness of the ERR index, relax the hypothesis of the net cash flow discount, use the numerical example to calculate two External rate of return curve, and produce a intersection similar to the Fisher point. However, the numerical value of the intersection is not equal to that of the Fisher point, and this will cause new chaos when using the ERR to choose the repelling programs. According to all these discoveries, we can deem that the index of ERR is irrational.At last, we can draw the conclusions:(1)The index of ERR has a unique solution compared with the IRR and this is the only advantage compared with the IRR.(2)The iterative trial and interpolation are generally used to calculate the index of ERR. It is not easier than to calculate the IRR.(3)The index of ERR can't be used directly to choose the repelling programs, so it is less convenient than the IRR. Furthermore, the index of ERR can produce the difference between the numerical value of the intersection similar to the Fisher point and that of the Fisher point and this can lead to the chaos of choice. So we suggest that the index of ERR should be deleted from the evaluation index system.
引文
[1]千住镇雄,伏见多美雄.经济性工学基础[M].东京:日本能率协会,1982.
[2]国家发改委,建设部.建设项目经济评价方法与参数(第3版)[M].北京:中国计划出版社,2006.
[3]里格斯J L.工程经济学[M].北京:中国财政经济出版社,1989.
[4]爱德华J布洛切,康H陈,托马斯W林.成本管理——计划与决策[M].北京:华夏出版社,2002.
[5]艾伦D H.工程项目经济评价入门[M].北京:化学工业出版社,1980.
[6]注册咨询工程师(投资)考试教材编写委员会.现代咨询方法与实务[M].北京:中国计划出版社,2003.
[7]程兴华.现代企业投资决策管理[M].上海:立信会计出版社,1997.
[8]傅家骥,吴贵生.技术经济学[M].北京:中国经济出版社,1987:165-167.
[9]郑策.石油化工技术经济学[M].北京:中国石油出版社,1991:112-114.
[10]余绪缨.管理会计学[M].北京:中国人民大学出版社,1999:244-248.
[11]陆宁,王成玉,蔡爱云,等.外部收益率替代内部收益率的适性分析[J].长安大学学报:社会科学版,2005,7(1):47-50.
[12]王曙光.用外部收益率取代内含报酬率的思考[J].商业研究,2003(8):101-102.
[13]亨利·马尔科姆·斯坦纳.工程经济学原理(第2版)[M].北京:北京经济科学出版社,2000:216,163,176.
[14]布西L E.工业投资项目的经济分析[M].北京:机械工业出版社,1985:169-192.