【正文】 據(jù)福利經(jīng)濟學理論判定。 2023 Thomson SouthWestern 消費者、生產(chǎn)者與市場效率 ? 福利經(jīng)濟學 –市場均衡使利益最大化，即使產(chǎn)品的消費者和生產(chǎn)者的總利益最大化。 ? 它衡量買者對物品的評價是多少。 2023 Thomson SouthWestern Using the Demand Curve to Measure Consumer Surplus ? The area below the demand curve and above the price measures the consumer surplus in the market. 169。 ? 它衡量了賣者從參與市場中得到的利益。 2023 Thomson SouthWestern 利用供給曲線衡量生產(chǎn)者剩余 ? 價格以下和供給曲線以上的面積衡量市場的生產(chǎn)者剩余。 2023 Thomson SouthWestern The Benevolent Social Planner ? Efficiency is the property of a resource allocation of maximizing the total surplus received by all members of society. 169。 ? 自由市場把物品的需求分配給可以以最低成本生產(chǎn)這些物品的賣者。 2023 Thomson SouthWestern 市場均衡的評價 ? 市場勢力 ? 如果一個市場系統(tǒng)不是完全競爭的，就會出現(xiàn)市場勢力。 Summary 169。 ? 生產(chǎn)者剩余衡量賣者從參與市場中得到的利益。 2023 Thomson SouthWestern ? 供給與需求的均衡使消費者與生產(chǎn)者剩余的總和最大化。 –市場均衡可以使買者和賣者的總利益最大化。 2023 Thomson SouthWestern 稅收如何影響市場參與者 ? 稅收在買者支付的價格和賣者得到的價格之間打入了一個楔子。 169。 –也就是說，決定于供給和需求的價格彈性。 2023 Thomson SouthWestern DEADWEIGHT LOSS AND TAX REVENUE AS TAXES VARY ? The Deadweight Loss Debate – Some economists argue that labor taxes are highly distorting and believe that labor supply is more elastic. – Some examples of workers who may respond more to incentives: ? Workers who can adjust the number of hours they work ? Families with second earners ? Elderly who can choose when to retire ? Workers in the underground economy (., those engaging in illegal activity) 169。 ? 但隨著稅收規(guī)模繼續(xù)增加，稅收收入反而減少，這是因為較高的稅收規(guī)模減少了更多的市場規(guī)模。 ? 總剩余（消費者剩余、生產(chǎn)者剩余和稅收收入之和）的減少被稱為稅收的無謂損失。 ? 稅收收入起初隨著稅收規(guī)模增加而增加。 2023 Thomson SouthWestern The Equilibrium Without Trade ? Results: ? Domestic price adjusts to balance demand and supply. ? The sum of consumer and producer surplus measures the total benefits that buyers and sellers receive. 169。 169。 2023 Thomson SouthWestern The World Price and Comparative Advantage 世界價格與比較優(yōu)勢 ? If the country decides to engage in international trade, will it be an importer or exporter of steel? ? 如果這個國家決定參與國際貿(mào)易，它將是鋼鐵進口國還是出口國？ 169。 2023 Thomson SouthWestern Application: International Trade ? What determines whether a country imports or exports a good? ? Who gains and who loses from free trade among countries? ? What are the arguments that people use to advocate trade restrictions? 169。 ? 這種行為變化使市場規(guī)模縮小到使總剩余最大化的水平之下。 ? 相反，隨著稅收規(guī)模提高，稅收收入先是增加，然后隨著稅收規(guī)模越來越大，市場規(guī)模收縮非常之大，以至于稅收收入開始減少。 Figure 6 How Deadweight Loss and Tax Revenue Vary with the Size of the Tax Tax revenue Demand Supply Quantity 0 Price Q1 (a) Small Tax Deadweight loss PB Q2 PS 圖 6. 無謂損失和稅收收入如何隨著稅收規(guī)模而變動 稅收收入 需求 供給 數(shù)量 0 價格 Q1 (a) 小額稅 無謂損失 PB Q2 PS Figure 6 How Deadweight Loss and Tax Revenue Vary with the Size of the Tax Tax revenue Quantity 0 Price (b) Medium Tax PB Q2 PS Supply Demand Q1 Deadweight loss 圖 6. 無謂損失和稅收收入如何隨著稅收規(guī)模而變動 稅收收入 數(shù)量 0 價格 (b) 中額稅 PB Q2 PS 供給 需求 Q1 無謂損失 Figure 6 How Deadweight Loss and Tax Revenue Vary with the Size of the Tax Tax revenue Demand Supply Quantity 0 Price Q1 (c) Large Tax PB Q2 PS Deadweight loss 圖 6. 無謂損失和稅收收入如何隨著稅收規(guī)模而變動 稅收收入 需求 供給 數(shù)量 0 價格 Q1 (c) 大額稅 PB Q2 PS 無謂損失 169。 169。 2023 Thomson SouthWestern 無謂損失與貿(mào)易的好處 ? 稅收引起無謂損失是因為它使買者與賣者不能實現(xiàn)某些貿(mào)易的好處。 2023 Thomson SouthWestern 稅收如何影響市場參與者 ? 稅收收入 ? T = 稅收規(guī)模 ? Q = 物品銷售量 ? T ? Q = 政府的稅收收入 Figure 2 Tax Revenue Tax revenue (T Q) Size of tax (T) Quantity sold (Q) Quantity 0 Price Demand Supply Quantity without tax Quantity with tax Price buyers pay Price sellers receive 圖 2. 稅收收入 價格 0 數(shù)量 稅前數(shù)量 供給 需求 賣者得到 的價格 稅后數(shù)量 稅收規(guī)模 (T) 銷售量 (Q) 稅收收入 (T x Q) 買者支付 的價格 Figure 3 How a Tax Effects Welfare A F B D C E Quantity 0 Price Demand Supply = PB Q2 = PS Price buyers pay Price sellers receive = P1 Q1 Price without tax 圖 3. 稅收如何影響福利 數(shù)量 0 價格 需求 供給 Q1 A B C F D E Q2 征稅減少了消費者剩余 (用面積 B+C代表 )和 生產(chǎn)者剩余 (用面積 D+E代表 ) 稅收 = (B+D) 買者支付的價格 = PB P1 沒有稅收時的價格 = PS 賣者得到的價格 = 無謂損失 = (C+E) Figure 3 How a Tax Effects Welfare A F B D C E Quantity 0 Price Demand Supply = PB Q2 = PS Price buyers pay Price sellers receive = P1 Q1 Price without tax 圖 3. 稅收如何影響福利 數(shù)量 0 價格 需求 供給 Q1 A B C F D E Q2 買者支付的價格 = PB P1 沒有稅收時的價格 = PS 賣者得到的價格 = How a Tax Affects Welfare Without Tax With Tax Change Consumer Surplus A + B + C A (B + C) Producer Surplus D + E + F F (D + E) Tax Revenue none B + D + (B + D) Total Surplus A + B + C + D + E + F A + B + D + F (C + E ) The area C+E shows the fall in total surplus and is the deadweight loss of the tax. 稅收如何影響福利 沒有稅收時 有稅收時 變動 消費者剩余 A + B + C A (B + C) 生產(chǎn)者剩余 D + E + F F (D + E) 稅收收入 無 B + D + (B + D) 總剩余 A + B + C + D + E + F A + B + D + F (C + E ) C+E 的面積表示總剩余減少，而且是稅收的無謂損失。 2023 Thomson SouthWestern THE DEADWEIGHT LOSS OF TAXATION ? It does not matter whether a tax on a good is levied on buyers or sellers of the good . . . the price paid by buyers rises, and the price received by sellers falls. 169。 2023 Thomson SouthWestern 應(yīng)用：稅收的成本 169。 2023 Thomson SouthWestern ? 可以說使消費者和生產(chǎn)者剩余的總和最大化的資源配置是有效率的。 ? 消費者剩余可以通過找出需求曲線以下和價格以上的面積來計算。 2023 Thomson SouthWestern Evaluating the Market Equilibrium ? Externalities ? created when a market oute affects individuals other than buyers and sellers in that market. ? cause welfare in a market to depend on more than just the value to the buyers and cost to the selle