【正文】 行為準則便于理論分析； 2. 如果市場競爭機制是完善的，追求利潤的企業(yè)更有可能在市場競爭中生存。 65 5 利潤最大化行為準則的說明 ? 實際中企業(yè)的行為取決于企業(yè)的控制權掌握在所有者還是經營者手里。 事實上 ，這個經濟假設顯然是錯了 。 65 10 完全競爭市場的基本特征 ? There are many small firms, each producing an identical product and each too small to affect the market price. ? The perfect petitor faces a pletely horizontal demand curve. ? The extra revenue gained from each extra unit sold is therefore the market price. 65 11 說明 ? 一般教材關于完全競爭的假設： ?無數(shù)的買者與賣者 (numerous buyers and sellers)； ?產品沒有區(qū)別 (homogeneous products)； ?自由進入和退出 (free entry and exit)； ?完美和完全信息 (perfect or plete information)。 65 19 邊際收益 ? So what must be the relationship between the industry market price and the firm’s marginal revenue in a perfectly petitive industry? a) P MR b) P = MR c) P MR P = MR65 20 利潤 ? Profits are revenues, or Profits = total sales – total costs 65 21 利潤最大化條件 ? Maximum profit will occur when output is at that level where the firm’s marginal revenue is equal to its marginal cost. ? At the maximumpoint: MR = MC 65 22 利潤最大化條件的說明 產出變化 收益 損失 利潤變化 增加 1 單位 邊際收益 邊際成本 MR－ MC 減少 1 單位 邊際成本 邊際收益 MC－ MR 因此，當 MRMC 時增加產量， MRMC 時減少產量都可以增加利潤，當 MR=MC 時，利潤達到最大化。 65 55 凈經濟所得 P* A B E O Q* P P 生產付出的總成本 (負效用 )為 AEQ*O面積，得到的總效用為 BEQ*O面積，凈經濟收益為 BEA面積。 65 69 巨大的收入差異可以是有效的 ? In a world of perfect petition, the system of prices and markets may be one in which a few people have most of the ine and wealth, While the results can be a perfectly efficient oute. 65 70 什么樣的結果更公平 ? ? That is a normative (規(guī)范的 ) or prescriptive (說明性的 ) question, one that asks the question: “what should be?” ? Deciding such questions is more properly the domain (范圍 ) of politicians (政治家 ) and philosophers (哲學家 ) and voters at the ballot box (投票箱 ) or revolutionaries in the jungle (叢林 ). 65 71 實證經濟學 ? The more proper role of the economist is positive (實證的 ) or descriptive (描述的 ). ? Positive economics (實證經濟學 ) can offer great insights (洞察力 ) about how different types of government policies can affect the distribution of ine and consumption. ? Therefore, positive economic analysis is essential in many normative policy debates. End Of Lesson