MankiwEconomicsChap08中山大学吴柏林教授〔曼昆·经济学原理〕绝密资料.ppt

* 22 * 22 * 31 * 31 * 31 * 31 * * * * * 9 * 9 * 14 * 14 * 23 * 23 * 23 * 23 * 31 * 31 * 31 Summary Taxes have a deadweight loss because they cause buyers to consume less and sellers to produce less. This change in behavior shrinks the size of the market below the level that maximizes total surplus. Summary As a tax grows larger, it distorts incentives more, and its deadweight loss grows larger. Tax revenue first rises with the size of a tax. Eventually, however, a larger tax reduces tax revenue because it reduces the size of the market. Graphical Review The Effects of a Tax... Price 0 Quantity Quantity without tax Supply Demand Price without tax Price buyers pay Quantity with tax Size of tax Price sellers receive Tax Revenue... Price 0 Quantity Quantity without tax Supply Demand Price sellers receive Quantity with tax Size of tax (T) Quantity sold (Q) Tax Revenue (T x Q) Price buyers pay How a Tax Affects Welfare... Quantity 0 Price Demand Supply Q1 A B C F D E Q2 Tax reduces consumer surplus by (B+C) and producer surplus by (D+E) Tax revenue = (B+D) Deadweight Loss = (C+E) Price buyers pay = PB P1 Price without tax = PS Price sellers receive = The Deadweight Loss... Quantity 0 Price Demand Supply Q1 PB Price = P1 without tax PS Q2 Size of tax Lost gains from trade Cost to sellers Value to buyers Reduction in quantity due to the tax Tax Distortions and Elasticities... Quantity Price Demand Supply 0 When supply is relatively inelastic, the deadweight loss of a tax is small. (a) Inelastic Supply Size of tax Tax Distortions and Elasticities... Quantity Price Demand Supply 0 Size of tax When supply is relatively elastic, the deadweight loss of a tax is large. (b) Elastic Supply Tax Distortions and Elasticities... Quantity Price Demand Supply 0 When demand is relatively inelastic, the deadweight loss of a tax is small. (c) Inelastic Demand Size of tax Tax Distortions and Elasticities... Quantity Price Demand Supply 0 Size of tax When demand is relatively