【正文】
的果農(nóng)出售的有機(jī)蘋果的價(jià)格比一般蘋果貴 50%,這一比例遠(yuǎn)遠(yuǎn)高于一般蘋果和有機(jī)蘋縣之間的生產(chǎn)或本差異。而且從長期來看,企業(yè)之間的競爭總能使價(jià)格降到收益彌補(bǔ)成本的水平。– 按所在組群實(shí)施差別化定價(jià):如對(duì)老年人打折、。老人和學(xué)生可能是弱勢(shì)群體,但同時(shí)與他的弱勢(shì)相連的可能是他們對(duì)食物、音樂會(huì)門票的需求彈性相對(duì)較高(相對(duì)于一般大眾來說)。? 通過這種方式,全部消費(fèi)者剩余都被生產(chǎn)者拿走QDMCQFirstDegree PriceDiscrimination in PracticeQuantityDMRMC$/QP2P3P*4P5P6P1Six prices exist resultingin higher profits. With a single priceP*4, there are few consumers andthose who pay P5 or P6 may have a surplus.QSecondDegree Price DiscriminationQuantity$/QDMRMCACP0Q0Without discrimination: P = P0 and Q = Q0. With seconddegreediscrimination there are threeprices P1, P2, and P3.(. electric utilities)P1Q11st BlockP2Q2P3Q32nd Block 3rd BlockSeconddegree pricediscrimination is pricingaccording to quantityconsumedor in blocks.? 二級(jí)歧視的一種形式:兩步收費(fèi)? 兩步收費(fèi):既收一次性入門費(fèi),又收使用費(fèi)如果 P = Q, MC = 確定最優(yōu)的入門費(fèi)? 當(dāng) P = , 你買 4扎啤酒? 最高的入門費(fèi)為一個(gè)三角形面積– 高為 4,底為 4– (1/2)高 X底? 最高入門費(fèi)為 元? 壟斷 : QM = 2, PM = Q4QMPM=入門費(fèi)DPrice Discrimination? Third Degree Price Discrimination1) Divides the market into twogroups.2) Each group has its own demand function.? 如果兩個(gè)顧客,一為男性,另一個(gè)為女性,分別與一名新的轎車經(jīng)銷商就一輛新車進(jìn)行討價(jià)還價(jià),兩個(gè)碰巧是用同樣的討價(jià)還價(jià)說辭,平均來看,男性顧客會(huì)獲得更多的優(yōu)惠,為什么?按不同成員所在組群進(jìn)行差別化定價(jià) ? 食品店可以根據(jù)年齡對(duì)老年顧客購買東西按一定比例打折扣;劇場(chǎng)有時(shí)會(huì)對(duì)老年人打折;交響樂團(tuán)會(huì)對(duì)學(xué)生訂票打折;一個(gè)更為一般的例子是公交公司對(duì)老年人票和學(xué)生票實(shí)行特價(jià)。? 包裝食品如速食谷類食品的制造商,在所謂的廣告郵購單上( advertising mailers)會(huì)分發(fā)其產(chǎn)品的贈(zèng)券,這些贈(zèng)券可免費(fèi)提供。正如一位農(nóng)場(chǎng)主所言: “一如在衣業(yè)中其他領(lǐng)域發(fā)生的故事一樣,一旦人們發(fā)現(xiàn)在某一領(lǐng)域有利可圖,這一利潤字間通常只能持續(xù)很短時(shí)間。 USDA將會(huì)對(duì)有機(jī)食品的生產(chǎn)展開全程檢測(cè).從衣場(chǎng)的主產(chǎn)過程到工廠制作等,直至該食品最終到達(dá)超市或者餐館。所以, MR也就是總收益曲線的斜率 (TR)需求和邊際收益 銷售數(shù)量 (Q) 價(jià)格 TR = P ? Q MR = ?TR/?Q0 $1 2 3 4 5 6 7 $ 0 $ $ $ $ $ $ $ $ $ $ $ $ $0 $ 需求 邊際收益和總收益Panel A Panel B需求 邊際收益? 當(dāng)需求是線性函數(shù)時(shí), Q=a - bP, 反需求函數(shù)為:? P = ( a/b) + ( 1/b) Q– 邊際收益也是線性函數(shù),與縱軸的交點(diǎn)恰好是需求曲線與縱軸的交點(diǎn),它的斜率是需求曲線斜率的兩倍 – MR = ( a/b) +2( 1/b) Q需求 邊際收益和彈性邊際收益和彈性? 對(duì)任何需求曲線和邊際收益曲線來說,邊際收益、價(jià)格和彈性的關(guān)系可被表示為:廠商實(shí)現(xiàn)利潤最大化的原則:? 廠商利潤最大化的條件: 邊際收益 =邊際成本 總利潤 =總收益 總成本即 π(Q) =TR(Q) – TC(Q) dπ/dQ=dTR /dQ dTC /dQ =0 dTR /dQ=dTC /dQ MR=MC與決策無關(guān)的沉沒成本、固定成本和平均成本? 沉沒成本 Sunk costs– 已經(jīng)支出且無法再收回的成本? 固定成本 Fixed costs– 不隨產(chǎn)量變化而變化的成本? 平均成本 Average (or unit) costs– 每單位成本平均分?jǐn)偟降目偝杀? 這些成本不影響邊際成本也就與最優(yōu)化決策無關(guān)96Sunk Costs Example? Suppose a pharmaceutical pany(藥業(yè)公司) owns a piece of land that it can develop.? The pany has two subsequent decisions to make: – At time 0: Whether to sell the land for $ or build an endostatin(抗癌) plant on it at a cost of $– At time 1: If it builds the plant, whether to shut it down, to operate at low capacity, or to operate at high capacity97Sunk Costs Example? The profits from the different outes are (in millions of dollars):– Decision Revenue Cost Profit– Sell land – Build, shut down – Build, low output – Build, high output ? Hence, at time 0, the pany should sell the land98Sunk Costs Example? Suppose now that for some reason the decision to build the plant is made at time 0 ? The payoffs to the different strategies at time 1 are (in millions of euros):– Decision Profits Gross of S. C. Net of S. C.– Shut down – Low output – High output ? Hence, the sunk cost does not affect the optimal decision at time 1 – to shut down!99Sunk Costs? There are numerous instances where investors (and governments!) keep on investing in lossmaking project just because they have already wasted a lot of money on them? The tendency for people to let sunk costs affect their decisions is called the fallacy of sunk cost (or the Concorde fallacy or throwing good money after bad)在圖形中加入平均收益(反需求函數(shù))和邊際收益 AR大于 AC的區(qū)域(圖 a