乔纳森·格鲁伯-财政学（第五版）gruber_5e_lecture_slides_ch07.pptxVIP

Copyright ? 2010 Worth Publishers 7Heather Luea and Dan SacksP R E P A R E D B Y7.1 Optimal Provision of Public Goods7.2 Private Provision of Public Goods7.3 Public Provision of Public Goods7.4 ConclusionPublic Goods 7Public Goods: Trash Collection in Dhaka, BangladeshWhy don’t people pay to have their neighbor’s trash collected? No one wants to pay, but everyone wants someone else to pay.Private trash collection, financed by a voluntary fee paid by neighborhood residents, faces the classic free rider problem.Goods that suffer from this free rider problem are known in economics as public goods. 7.1Pure public goods: Goods that are perfectly non-rival in consumption and are non-excludable.Non-rival in consumption: One individual’s consumption of a good does not affect another’s opportunity to consume the good.Non-excludable: Individuals cannot deny each other the opportunity to consume a good.Impure public goods: Goods that satisfy the two public good conditions (non-rival in consumption and non-excludable) to some extent, but not fully.Public Goods: A taxonomy 7.1Defining Pure and Impure Public GoodsIs the good rival in consumption?Is the good excludable?YesNoYesPrivate good(ice cream)Impure public good(cable TV)NoImpure public good(crowded sidewalk)Public good(defense) 7.1How much of the public good should society provide?Markets will not provide the correct amount.To answer this question, start by reconsidering the market for a private good like ice cream cones.Ben and Jerry have different tastes for ice cream (ic), relative to the other good (c). How does the market aggregate their preferences?Optimal Provision of Public Goods 7.1?Horizontal Summation in Private Goods Market Price of ice cream conePrice of ice cream conePrice of ice cream coneQuantity of conesQuantity of conesQuantity of cones$2$2$2213000DBDJES = SMCDB&J = SMBTo find the social demand curve, add quantity at each price and sum horizontally.Horizontal Summation in Private Goods Market7.1Ben’s Ma