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Re:我所知道的张五常(之十)(李俊慧) 作者:dzz 发表时间:2001年5月24日 12:38 “张五常跟我们说,“profit maximazation”的错误,是他的老师Alchian跟他说的。”,“利润(率)是到处一样的,不是个人所能决定(最大化)的,是市场上各方竞争力量作用之下形成的均势,就如价格不是个人所能决定的一样。所以也没有“利润最大化”这回事。” 利润率到处一样是不错。为什么一样?是因为竞争的结果。怎样竞争?个人寻找合适的投资机会是方式之一,例如“如果某一行业或生产某一产品的利润率高于利息率,人们就会蜂涌着将钱从银行提出来投入到那个行业或产品的生产上。”这种行为是不是利润最大化?当然是!利润率到处一样是利润最大化的结果。说利润率到处一样因而没有利润最大化是本末倒置、逻辑混乱。 Re:我所知道的张五常(之十)(李俊慧) 作者:bear 发表时间:2001年5月24日 17:58 dzz最後第二句我沒看明白,再說一下? LAWS DEFINE THE BOUNDARY OF FREEDOM.FREEDOM IS THE RIGHT TO CHOOSE. Re:我所知道的张五常(之十)(李俊慧) 作者:Ah sa 发表时间:2001年5月24日 20:46 bear, dzz: Suppose a firm has cost C and expect to receive revenue R. Standard economics says expected profit=R-C. According to Cheung, the cost of running the firm is more than C. Because the frim also forgo the opportunity of selling the firm at its expected value (R-C). Therefore, the "expected profit" should be R-C-(R-C)=0! This conclusion is based on two things: (1) expectation is correct (2) market for your firm (if you have no buyer, your opportunity of running the firm is just C) So, Cheung just relabel everything. Standard economics labels R-C as "expected profit". He labels it "rent". Standard economics labels the "unexpected increase in profit" as "unexpected profit". He labels it "profit". Redefining things is good if it helps clarification & communication. In this case, it just increases ambiguity. The problem is that the terms "profit" & "rent" are well accepted terminologies, changing their meanings will only mislead students & cause communication problem. It would be so much better that Cheung relabels his rent & profit by alpha & beta. (But in that case, you will realise that he didn't point out anything at all) I won't say he's wrong, but it is just another example that he uses idiocyncratic definition that no one (except Hongkong A-level economics students) cares. If you believe in market force, the frequency of economists using his definition (almost zero) suggests how useful these definitions are! 学无新旧,学无中西,中国今日实无学之患,而非中学西学偏重之患 -- 王国维 Re:我所知道的张五常(之十)(李俊慧) 作者:bear 发表时间:2001年5月25日 15:45 Ah sa : 我一直以為要看理論推測得準不準的。不是嗎?如果無人理會所謂的「推背圖」或「燒餅歌」,而它們又都對了,就算它們把意思收起來不明示,也是準的預言。聖經的啟示錄也一樣。科學推測要明確,更易判斷。 LAWS DEFINE THE BOUNDARY OF FREEDOM.FREEDOM IS THE RIGHT TO CHOOSE. Re:我所知道的张五常(之十)(李俊慧) 作者:Ah sa 发表时间:2001年5月26日 09:28 bear: Let's see our agreements & disagreements. We both agree that: (1) To verify whether a model is useful, we should test the predictive power of the implications. (2) Definition has no right or wrong. ........................................... In addition, I point out the followings (1) Cheung just relabel the convetional term "expected profit" by "rent", and the term "unexpected profit" by "profit". Nothing new. (2) I am NOT saying this relabelling is "false". But not a "GOOD" one. Redefining things is good if it helps clarification & communication. But in this case, it just increases ambiguity. The problem is that the terms "profit" & "rent" are well accepted terminologies, changing their meanings will only mislead students & cause communication problem. It would be so much better that Cheung relabels his rent & profit by alpha & beta. (3) bear thinks that whether a defnition is good or bad is NOT significant. I think it is not significant in terms of testing models. But it is significant in terms of economic education & communication. Good definition is as important as a good translation. Read this dialogue: "张五常问:“profit你们怎么翻译?” 我答:“利润!” 张五常说:“错!” 我问:“那应该译成什么?” 张五常答:“应该是‘盈利’。”" Do you think that Cheung's arguement about translation is not significant (in terms of education & communication), bear? 学无新旧,学无中西,中国今日实无学之患,而非中学西学偏重之患 -- 王国维 Re:我所知道的张五常(之十)(李俊慧) 作者:dzz 发表时间:2001年5月26日 11:24 bear, 如果利润率不一样,出于自利和理智,人们会把钱投到利润率高的地方(亦即人们追求利润最大化),从而导致高利润率的地方利润率下降、低利润率的地方利润率升高。因此利润率到处一样是果不是因。 Ah sa, 谢谢解释。 Re:我所知道的张五常(之十)(李俊慧) 作者:bear 发表时间:2001年5月27日 17:39 DZZ與AH SA的解釋好象不同。 最後是涉及到語言的問題,其一,不是主流的定義難以流傳,但我不知主流形成的條件,但服從主流讀者可能會多一點。其二,只要知自道自己定義的與主流不同,在文章中說明白了,邏輯也至於一定錯,可能對得很精彩,其定義也很「正統」(例如:追溯回定義最古老的起源),但不服從習慣的用法。但這是造成理解的困難了。其三,譯名也不易。"COST"的定義就有很多個版本的說法,不知那個「好」?有的字的用法與含意數十年後就在大眾用語中變了,但學術含意不變,有時看起來不合時宜。最後,名稱之外,含意或概念最重要,主流的名稱,一人不用是影響不了什麼的。與定價問題一樣,共通的用法(市價)與個人的用法(個人的開價)有微妙的關係。 LAWS DEFINE THE BOUNDARY OF FREEDOM.FREEDOM IS THE RIGHT TO CHOOSE. Re:我所知道的张五常(之十)(李俊慧) 作者:dzz 发表时间:2001年5月27日 23:20 Ah sa和我说的是不同的事,当然不一样。 Ah sa说的是张五常把现有的经济学名词重新起名,不利于经济学的学习和交流。 我说的是lijunhui关于没有利润最大化的观点不对。请注意这里的利润是主流经济学中的利润。