第11章 就业11.doc

BOOK IV THE INDUCEMENT TO INVEST 第四编：投资诱导 CHAPTER 11 THE MARGINAL EFFICIENCY OF CAPITAL 第十一章：资本边际效率 I WHEN a man buys an investment or capital-asset, he purchases the right to the series of prospective returns, which he expects to obtain from selling its output, after deducting the running expenses of obtaining that output, during the life of the asset. This series of annuities Q1, Q2 . . . Qn it is convenient to call the prospective yield of the investment. 每个人购买一件投资品或资本资产时，他是在购买能得到的一系列未来收益权。未来收益，是他预期在资产的寿命期间出售该资产的产品减去为得到该产品而支出的营业费用以后所得到的收入。假定该资产的寿命为Q1, Q2 . . . Qn，这一系列的年收入称之为预期收益。 Over against the prospective yield of the investment we have the supply price of the capital-asset, meaning by this, not the market-price at which an asset of the type in question can actually be purchased in the market, but the price which would just induce a manufacturer newly to produce an additional unit of such assets, i.e. what is sometimes called its replacement cost. The relation between the prospective yield of a capital asset and its supply price or replacement cost, i.e. the relation between the prospective yield of one more unit of that type of capital and the cost of producing that unit, furnishes us with the marginal efficiency of capital of that type. More precisely, I define the marginal efficiency of capital as being equal to that rate of discount which would make the present value of the series of annuities given by the returns expected from the capital-asset during its life just equal to its supply price. This gives us the marginal efficiencies of particular types of capital-assets. The greatest of these marginal efficiencies can then be regarded as the marginal efficiency of capital in general. 与投资预期收益相对应的是资本资产的供给价格，其意义并不是指一件资产在市场上实际上被买到的价格，而是指能诱导制造商生产出相同的资本资产的价格，即有时也被称为重置成本的概念。从资本资产的预期收益和它的供给价格或重置成本之间的关系可以得到资本资产增加一个单位的预期收益和该单位的重置成本之间的关系。这种关系为我们提供了资本边际效率的概念。更确切地说，我把资本边际效率定义为一种贴现率，而根据这种贴现率，在资本资产的寿命期间所提供的预期收益的现值能等于该资本资产的供给价格。这是某一具体种类的资本资产的边际效率，各种不同的资本资产的边际效