哈维罗森 财政学 第六版 Chap04 Public GoodsWord

　　哈维罗森 财政学 第六版

　　Chapter 4 - Public Goods

　　哈维罗森 财政学 第六版

　　Public Goods Defined Pure public goods share two characteristics– Nonrival – Cost of another person consuming the good is zero– Nonexcludable – Very expensive to prevent others from consuming the good

　　哈维罗森 财政学 第六版

　　Examples of public and private goods Public Goods– National defense

　　Private goods– Pizza

　　– House cleaning in an apartment with many roommates– Fireworks display – Music file sharing – Uncongested freeway

　　– Health care– Congested freeway – Public housing

　　哈维罗森 财政学 第六版

　　Valuation of public goods Everyone consumes same quantity of public good

　　Marginal benefit of public good varies by person– In the housecleaning example, different roommates value the clean apartment differently.4

　　哈维罗森 财政学 第六版

　　Impure public goods Most goods that are thought of as public goods may not strictly satisfy the nonrival or nonexcludable assumption.– A scenic view is a public good without congestion, but the quality diminishes as more the number of sightseers increases. – Thus, a scenic view becomes rival.5

　　哈维罗森 财政学 第六版

　　Private goods can be provided by the public sector These are called “publicly provided private goods.”

　　Key criteria: is the good rival and excludable? Public housing is rival (one family consumes one apartment) and excludable (easy to prevent consumption).

　　哈维罗森 财政学 第六版

　　Efficient provision of private goods Derivation of aggregate demand Each person’s demand curve represents the willingness-to-pay for an additional unit of a good. Private good: holding P constant, add together individual quantities to get Q. Horizontal summation7

　　哈维罗森 财政学 第六版

　　Figure 4.1

　　哈维罗森 财政学 第六版

　　Equilibrium in private goods market Equilibrium where supply curve intersects aggregate demand curve.

　　Everyone pays the same price, P. Individuals consume different quantities, Q. Pareto efficient.9

　　哈维罗森 财政学 第六版

　　Efficient provision of public goods Consider a fireworks display as a public good – it is nonrival and nonexcludable.

　　Bigger displays give higher benefit. Public good: holding Q constant, add together individual willingness-to-pay to get P. Vertical summation.

　　哈维罗森 财政学 第六版

　　Figure 4.4