大学课件：资源与环境经济学Chapter 9-1.ppt

1、Chapter 9Replenishable But Depletable Resources:Water9.1 IntroductionMain contents:Examining the likelihood and severity of water scarcityDefining the efficient allocation of ground and surface water over time and comparing these allocation to current practiceExamining the menu of opportunities for

2、meaningful institutional reform9.2 The Potential For Water ScarcityTwo rather different sources of available water supplies:Surface water which consists of the fresh water in rivers,lakes,and reservoirs that collects and flows on the earths surface.Groundwater which collects in porous layers of unde

3、rground rock known as acquifers.9.2 The Potential For Water ScarcityTo water scarcity,quantity of water is not the only problem.Quality is also a problem.9.3 The Efficient Allocation of Scarce WaterWhat efficiency means for the allocation of water depends crucially on whether surface water or ground

4、water is being tapped.In the absence of storage,the problem with surface water is to allocate a renewable supply among competing users.Intergenerational effects are less important as future supplies depend on natural phenomena (such as precipitation)rather than on current withdraw practices.For grou

5、ndwater,on the other hand,withdrawing water now does affect the resources available to future generations.In this case,the allocation over time is a crucial aspect of the analysis.9.3 The Efficient Allocation of Scarce WaterAn efficient allocation of surface water:Must strike a balance among a host

6、of competing users Must supply an acceptable means of handling the year-to-year variability in surface water flow.9.3 The Efficient Allocation of Scarce WaterHow to strike a balance among a host of competing users?The water should be allocated so that the marginal net benefit is equlized for all use

7、s.Figure 10.29.3 The Efficient Allocation of Scarce WaterHow to deal with fluctuations in supply?As long as the supply level can be anticipated,the equal marginal net benefit rule still applies,but different supply levels may imply very different allocations among users.This is an important attribut

8、e of the problem because it implies that simple allocation rules,such as each user receiving a proportion of the available flow or high-priority users receiving a guaranteed amount,are not likely to be efficient.9.3 The Efficient Allocation of Scarce WaterAnalyzing the efficient allocation of ground

9、water,the depletable nature of groundwater supplies be explicitly taken into account.9.3 The Efficient Allocation of Scarce WaterThe efficient allocation of groundwater over time.The efficient allocation should consider the marginal user cost.The efficient extraction path for constant demand involve

10、s declining use of groundwater over time.The marginal extraction cost would rise over time as the water table fell.Pumping would stop either whenThe water table ran dryThe marginal cost of pumping was either greater than the marginal benefit of the water or greater than the marginal cost of acquirin

11、g water from some other source.9.3 The Efficient Allocation of Scarce WaterThe efficient allocation of groundwater over time.Abundant surface water in proximity to the location of the groundwater could serve as a substitute for groundwater,effectively setting an upper bound on the marginal cost of e

12、xtraction.In efficient groundwater markets,the water price would rise over time.9.4 The Current Allocation SystemAllocation system and its efficiency我国水资源的分配体系及其有效性分析：我国水资源的分配体系：通过对取水许可的管理来实施目前尚无明确的分配标准，主要是根据取水户提出的取水计划及各级水行政主管部门制定的用水计划来核定、审批。各级水行政主管部门在分配其取水许可量时按“优先顺序”分配，即首先满足城乡居民生活用水，统筹兼顾农业、工业用水和航运需

13、求，并维持生态环境用水。各级水行政主管部门根据取水户的实际取水量征收水资源费，实行有偿使用。我国水资源的分配体系：定额管理工业用水农业用水居民生活用水可交易的取水许可证我国水资源的分配体系及其有效性分析：我国水资源分配的有效性分析：取水许可证制度：分配标准不明确，不能保证水量分配的公平性，也不能有效控制节约用水。水资源分配的优先顺序不能保证用水的公平与效率。有偿使用制度执行不彻底。定额管理用水计量可交易的取水许可证9.4 The Current Allocation SystemSources of inefficiency:Restrictions on transfersWater pri

14、cingCommon property problems9.4 The Current Allocation SystemRestrictions on transfersWith a well-structured system of water property rights,efficiency can be a direct result of the transferability of the rights.Users receiving low marginal net benefits from their current allocation would trade thei

15、r rights to those who would receive higher net benefits.Both parties would be better off.9.4 The Current Allocation SystemWater pricingBoth the level of prices and the rate structure are at faultIn general,the price level is too lowThe rate structure does not adequately reflect the costs of providin

16、g service to different types of customers.9.4 The Current Allocation SystemWater pricingFor surface water the rates are too low for two reasons:Historic average costs are used to determine ratesMarginal scarcity rent is rarely included.Efficient pricing requires the use of marginal,not average,cost,

17、including marginal user cost.9.4 The Current Allocation SystemCommon property problemsThe allocation of groundwater must confront one additional problem.When many users tap the same aquifer,that aquifer becomes a common property resource.Tapping a common property resource will tend to deplete it too

18、 rapidly,users lose the incentive to conserve.The marginal scarcity rent will be ignored.9.4 The Current Allocation SystemCommon property problemsFor common property resources,economic theory suggests several direct consequences.Pumping costs would rise too rapidlyInitial prices would be too lowToo

19、much water would be consumed by the earliest users.9.5 Potential RemediesThe first reform would reduce the number of restrictions on water transfers.Allowing users to capture the value of water saved by permitting them to sell it would stimulate water conservation and allow the water to flow to high

20、er valued uses.9.5 Potential RemediesGetting the prices right is another avenue for reformA marginal cost pricing system should be used to determine the price of water.Government interventionDiscussion questions:What pricing system identified in Table 10.1 best describes the pricing system used to p

21、rice the water you use at your college or university?Does this pricing system affect your behavior about water use(length of showers,etc.)?How?Could you recommend a better pricing system in this circumstance?What would it be?Objectives&Requirements:Understand the potential for water scarcity Grasp the efficient allocation of scarce water Know the current allocation system and find the potential remedies