歐文·費雪
歐文·費雪：美國經濟學家、數學家，經濟計量學的先驅者之一，美國第一位數理經濟學家，耶魯大學教授，主要貢獻：貨幣理論原則
歐文·費雪生平簡介
歐文·費雪(Irving Fisher, 1867—1947)，1867年2月27日生於紐約州的少格拉斯。1890年開始在耶魯大學任數學教師，1898年獲哲學博士學位。同年轉任經濟學教授直到1935年、1926年開始在雷明頓、蘭德公司任董事等職。1929年，與J.A熊彼特、J.丁伯根等發起並成立計量經濟學會，1931～1933年任該學會會長。1947年4月29日卒於紐約市。
費雪是耶魯大學第一個經濟學博士，但卻是在耶魯大學數學系獲得這個學位。他的學位論文《價值與價格理論的數學研究》用定量分析研究效用理論，至今為經濟學家稱道。這篇論文奠定了他作為美國第一位數理經濟學家的地位。費雪涉獵的領域相當廣泛，據他的兒子I.N.費雪為他們寫的傳記所列，他一生共發表論著2000多種，合著400多種，用著作等身來形容並不為過。
費雪的一生也是頗多坎坷的。就人生而言，費雪的女兒瑪格麗特在1919年由於精神崩潰而去世。與費雪共同愉快地生活了47年的妻子瑪格麗特·哈澤德於1940年去世。費雪本人在1898年感染了當時被稱為不治之症的肺結核。就事業而言，費雪發明了可顯示卡片指數系統，並取得專利，辦了一個獲利頗豐的可顯示指數公司。後來該公司與競爭對手合並為斯佩里·蘭德 (Sperry Rand)公司。這項事業使他致富，但20世紀30年代大危機之前他借款以優惠權購買蘭德公司股份，大危機爆發後，他的股票成為廢紙。據他兒子估計，損失為800~1000萬美元，連妻子、妹妹和其他親屬的儲蓄都賠進去了。他一文不名，耶魯大學只好把他的房子買下，再租給他住，以免被債主趕出去。他的名聲亦受到打擊。
1929年他在大危機中受到沉重打擊，但仍在1930年出版了代表作《利息理論》，在1932年出版了《繁榮與蕭條》，在1933年出版了《大蕭條的債務通貨緊縮理論》，在1935年出版了《百分之百的貨幣》。
盡管人生有如此多的挫折，費雪還是健康地活了80歲，這就在於他健康的心態。他深信人性本善，而人類優良天性的保持，有賴於優生。他組織優生學研究會(Eugenics Research Association)、美國優生學會(American Eugenics Society)，並任主席，親自寫成《民族活力報告》(Report of National Vitality)，提出建議。相信人性之善，是一個人心態健康的出發點。
1898年費雪患肺結核病之後，深感衛生保健的重要。他在1913年發起成立生命延續研究所(Life Extension Institute),並擔任該所保健指導委員會(Hygiene Reference Board)主席。他與該所醫學專家費斯克(Fisk)合寫了一本《如何生活》(How to Live)的書，暢談養生之道。該書觀念新穎而又切合實際，成為美國大學和高中的衛生保健教科書，共印行90版次，在美國銷量達40萬冊之多，亦有德、法、日等十幾種文字的譯本，比他的經濟學名著影響要大得多。他反對縱欲，主張禁酒，素食主義，鍛煉身體，養成良好衛生習慣，以及呼吸新鮮空氣。這恐怕是他的肺結核在3年後痊愈，他又精力充沛地投入研究工作，並取得了許多成就的原因。他的主要貢獻都是在這次病後做出的。
費雪還是一個關懷人類的世界和平主義者，他在1922年寫了《聯盟或戰爭》(League orWar)一書，主張美國放棄孤立主義，參加國際聯盟，為世界和平而努力。
歐文·費雪對經濟學的貢獻
費雪被公認為美國第一位數理經濟學家，他使經濟學變成了一門更精密的科學。他提高了現代對於貨幣量和總體物價水平之間關系的認識。他的交換方程大概是解釋通貨膨脹的原因的理論中最成功的。費雪認為可以保持總體物價水平的穩定，而價格水平的穩定會使得整個經濟保持穩定。1923年，他創辦了數量協會，是第一家以數據形式向大眾提供系統指數信息的組織。費雪是經濟計量學發展的領導者，加大了統計方法在經濟理論中的應用。
在經濟學中，費雪對一般均衡理論、數理經濟學、物價指數編制、宏觀經濟學和貨幣理論都有重要貢獻。費雪的代表作之一是1922年出版的《指數的編制》，這本書利用時間逆轉測驗法(time reversal test)和因子逆轉測驗法(factor reversal test)編制物價指數，對以後物價指數的編制影響頗大。
在今天人們仍然經常提到費雪是由於他對貨幣數量論和宏觀經濟學的貢獻。這方面他的代表作是《貨幣的購買力》 (1911)和《利息理論》。美國加州柏克利大學經濟學教授J.B.迪龍(J.B.De Long)在評論貨幣主義時把費雪稱為「第一代貨幣主義者」。這就是指費雪的貨幣數量論是最早的貨幣主義。費雪貨幣數量論的中心是交易總量 (T)乘價格(P)等於貨幣量(M)乘貨幣流通速度(V)(T·P=M·V)，當T和V不變時，物價水平(P)取決於貨幣數量(M)。這也正是弗里德曼現代貨幣數量論的中心思想。費雪提出，通貨膨脹率加實際利率等於名義利率，強調了預期通貨膨脹對名義利率一對一的影響。這種觀點被稱為費雪效應，現在仍是每一本宏觀經濟學教科書的基本內容。
費雪對經濟學的主要貢獻是在貨幣理論方面闡明了利率如何決定和物價為何由貨幣數量來決定，其中尤以貿易方程式（也作費雪方程式）為當代貨幣主義者所推崇。
費雪方程式是貨幣數量說的數學形式，即MV=PQ。其中M為貨幣量，V為貨幣流通速度，P為價格水平，Q為交易的商品總量。該方程式說明在V、P比較穩定時，貨幣流通量M決定物價P。
費雪還對經濟計量學、價值和價格理論、資本理論以及統計學等有所貢獻。
歐文·費雪的著作
主要著作有
- 《價值和價格理論的數學研究》（1892）
- 《資本和收入的性質》（1906）
- 《利息率》（1907）
- 《貨幣的購買力：其決定因素及其與信貸、利息和危機的關系》（1911）
- 《指數的編制》（1922）
- 《利息理論》（1930）
- 《通貨膨脹》（1933）
- 《百分之百的貨幣》（1935）等。
Irving Fisher
Irving Fisher (1867-1947)
Irving Fisher was one of America's greatest mathematical economists and one of the clearest economics writers of all time. He had the intellect to use mathematics in virtually all his theories and the good sense to introduce it only after he had clearly explained the central principles in words. And he explained very well. Fisher's Theory of Interest is written so clearly that graduate economics students, who still study it today, often find that they can read—and understand—half the book in one sitting. With other writings in technical economics, this is unheard of.
Although he damaged his reputation by insisting throughout the Great Depression that recovery was imminent, contemporary economic models of interest and capital are based on Fisherian principles. Similarly, monetarism is founded on Fisher's principles of money and prices.
Fisher called interest "an index of a community's preference for a dollar of present [income] over a dollar of future income." He labeled his theory of interest the "impatience and opportunity" theory. Interest rates, Fisher postulated, result from the interaction of two forces: the "time preference" people have for capital now, and the investment opportunity principle (that income invested now will yield greater income in the future). This reasoning sounds very much like B鰄m-Bawerk's. Indeed, Fisher's Theory of Interest was dedicated to "the memory of John Rae and of Eugen von B鰄m-Bawerk, who laid the foundations upon which I have endeavored to build." But Fisher objected to B鰄m-Bawerk's idea that roundaboutness necessarily increases production. Instead, argued Fisher, at a positive interest rate, no one would ever choose a longer period unless it were more productive. So if we look at processes selected, we do find that longer periods are more productive. But, he argued, the length of the period does not in itself contribute to productivity.
Fisher defined capital as any asset that produces a flow of income over time. A flow of income, said Fisher, was distinct from the stock of capital that generated it. Capital and income are linked by the interest rate. Specifically, wrote Fisher, the value of capital is the present value of the flow of (net) income that the asset generates. This still is how economists think about capital and income today.
Fisher also opposed conventional income taxation and favored a tax on consumption to replace it. His position followed directly from his capital theory. When people save out of current income and then use the savings to invest in capital goods that yield income later, noted Fisher, they are being taxed on the income that they used to buy the capital goods and then are being taxed later on the income that the capital generates. This, he said, is double taxation of saving, and biases the tax code against saving and in favor of consumption. Fisher's reasoning is still used by economists today in making the case for consumption taxes.
Fisher was a pioneer in the construction and use of price indexes. James Tobin of Yale has called Fisher "the greatest expert of all time on index numbers." Indeed, from 1923 to 1936, his own Index Number Institute computed price indexes from all over the world.
Fisher was also the first economist to distinguish clearly between real and nominal interest rates. He pointed out that the real interest rate is equal to the nominal interest rate (the one we observe) minus the expected inflation rate. If the nominal interest rate is 12 percent, for example, but people expect inflation of 7 percent, then the real interest rate is only 5 percent. Again, this is still the basic understanding of modern economists.
Fisher laid out a more modern quantity theory of money (i.e., monetarism) than had been done before. He formulated his theory in terms of the Equation of Exchange, which says that MV = PT, where M equals the stock of money; V equals velocity, or how quickly money circulates in an economy; P equals the price level; and T equals the total volume of transactions. Again, modern economists still draw on this equation, although they usually use the version MV = Py, where y stands for real income.
The equation can be a very powerful tool for checking the consistency of one's thinking about the economy. Indeed, Reagan economist Beryl Sprinkel, who was Treasury undersecretary for monetary affairs in 1981, used this equation to criticize his colleague David Stockman's economic forecasts. Sprinkel pointed out that the only way Stockman's assumptions about the growth of income, the inflation rate, and the growth of the money supply could prove true would be if velocity increased faster than it ever had before. As it turned out, velocity actually declined.
Irving Fisher was born in upstate New York in 1867. He gained an eclectic education at Yale, studying science and philosophy. He published poetry and works on astronomy, mechanics, and geometry. But his greatest concentration was on mathematics and economics, the latter having no academic department at Yale. Nonetheless, Fisher earned the first Ph.D. in economics ever awarded by Yale. Upon graduation he stayed at Yale for the rest of his career.
A three-year struggle with tuberculosis beginning in 1898 right Fisher with a profound interest in health and hygiene. He took up vegetarianism and exercise and wrote a national best-seller titled How to Live: Rules for Healthful Living Based on Modern Science, whose value he demonstrated by living until age eighty. He campaigned for Prohibition, peace, and eugenics. He was founder or president of numerous associations and agencies, including the Econometric Society and the American Economic Association. He was also a successful inventor. In 1925 his firm, which held the patent on his "visible card index" system, merged with its main competitor to form what later was known as Remington Rand and then Sperry Rand. Although the merger made him very wealthy, he lost a large part of his wealth in the stock market crash of 1929.
Selected Works
The Nature of Capital and Income. 1906.
The Purchasing Power of Money. 1911.
The Purchasing Power of Money, new and revised edition, 1922.
The Rate of Interest. 1907.
The Theory of Interest. 1930.
