【正文】 m (2) we see that each Pk is the ex rate of return of any share in class k。s worth of expected return must be the same for all shares of any given class。 The significance of this assumption is that it permits us to classify firms into groups within which the shares of different firms are homogeneous， that is， perfect substitutes for one another。 We shall assume that firms can be divided into equivalent return classes such that the return on the shares issued by any firm in any given class is proportional to (and hence perfectly correlated with) the return on the shares issued by any other firm in the same class。 Notice also that the uncertainty attaches to the mean value over time of the stream of profits and should not be confused with variability over time of the successive elements of the stream。 This way of characterizing uncertain streams merits brief ment。 This stream of ine， and hence the stream accruing to any share of mon stock， will be regarded as extending indefinitely into the future。 For reasons of space， however， and because the material is of interest in its own right， the presentation of the general equilibrium model which rounds out the analysis must be deferred to a subsequent paper。 Throughout these sections the approach is essentially a partialequilibrium one focusing on the firm and industry。 What appears to be keeping this line of development from achieving its promise is largely the lack of an adequate theory of the effect of financial structure on market valuations， and of how these effects can be inferred from objective market data。 Note that such a test is entirely independent of the tastes of the current owners， since market prices will reflect not only their preferences but those of all potential owners as well。 However， because the cost of capital has bee an essentially subjective concept， the utility approach has serious drawbacks for normative as well as analytical purposes。 Under these conditions the profit outes of alternative investment and financing decisions can be pared and ranked only in terms of a subjective utility function of the owners which weighs the expected yield against other characteristics of the distribution。 The profit oute， in short， has bee a random variable and as such its maximization no longer has an operational meaning。 These lines represent， in effect， attempts to extrapolate to the world of uncertainty each of the two criteriaprofit maximization and market value maximizationwhich were seen to have equivalent implications in the special case of certainty。 At the microeconomic level the certainty model has little descriptive value and provides no real guidance to the finance specialist or managerial economist whose main problems cannot be treated in a framework which deals so cavalierly with uncertainty and ignores all forms of financing other than debt issues。 Considered as a convenient approximation， the model of the firm constructed via this certaintyor certaintyequivalentapproach has admittedly been useful in dealing with some of the grosser aspects of the processes of capital accumulation and economic fluctuations。 It must be acknowledged that some attempt is usually made in this type of analysis to allow for the existence of uncertainty。 if it adds more to the market value of the firm than the costs of acquisition。 But profit will increase only if the expected rate of return， or yield， of the asset exceeds the rate of interest。 In much of his formal analysis， the economic theorist at least has tended to sidestep the essence of this costofcapital problem by proceeding as though physical assetslike bondscould be regarded as yielding known， sure streams。 專業(yè)文獻翻譯 題 目 ： 資本成本公司財務和投資理論 概論 學 院 ： 國際商學院 專 業(yè) ： 姓 名 ： 指導教師 ： 2021 年 4 月 5 日 The cost of Capital ， Corporation finance and the theory of investment By FRANCO MODIGLIAN1 AND MERTON H。 39。 According to the first criterion， a physical asset is worth acquiring if it will increase the profit of the owners of the firm。 e。 Indeed， in a world of sure returns， the distinction between debt and equity funds reduces largely to one of terminology。 No satisfactory explanation has yet been provided， however， as to what determines the size of the risk discount and how it varies in response to changes in other variables。 At the macroeconomic level there are ample grounds for doubting that the rate of interest has as large and as direct an influence on the rate of investment as this analysis would lead us to believe。 In this joint search to establish the principl