资源与环境经济学chapter

1、Chapter 5Sustainable Development: Defining The Concept1. IntroductionMain contents:Investigate one particular fairness concern-the treatment of future generations.Begin by considering a specific, ethically challenging situation-the allocation of a depletable resource over time.Defining what we mean

2、by a fair intertemporal allocation.Take this theoretical definition and consider how it can be made operationally measurable.2. A Two-Period ModelAccording to dynamic efficiency, the objective is to balance present and future uses of this resource by maximizing the present value of the net benefits

3、derived from the use of those resources. This implies a particular allocation of the resource across time.2. A Two-Period ModelAssume:We have a fixed supply of a depletable resource to allocate between two periods.Demand is constant in the two periods, the marginal willingness-to-pay is given by the

4、 formula P=8-0.4q, and marginal cost is constant at $2 per unit.2. A Two-Period ModelIf the total supply were 30 or greater, whats the efficient allocation between two periods?If the available supply is less than 30, suppose it is equal to 20, how do we determine the efficient allocation?Figure 5.12

5、. A Two-Period ModelHow to find the allocation that maximizes present value?The dynamically efficient allocation of this resource has to satisfy the condition that the present value of the marginal net benefit from the last unit in period 1 equals the present value of the marginal net benefit in per

6、iod 2.Figure 5.22. A Two-Period ModelAny efficient allocation method must take scarcity into account. Intemporal scarcity imposes an opportunity cost that we henceforth refer to as the marginal user cost.The marginal user cost is the present value of the forgone opportunities at the margin.Figure 5.

7、32. A Two-Period ModelAn efficient market would have to consider not only the marginal cost of extraction for this resource, but the marginal user cost as well.In the absence of scarcity, P=MCWith the scarcity, P=MC+MUC2. A Two-Period ModelBoth the size of the marginal user cost and the allocation o

8、f the resource between the two period is affecter by the discount rate.The general conclusion is that higher discount rates tend to skew resource extraction toward the present because they give the future less weight in balancing the relative value of present and future resource use.3. Defining Inte

9、rtemporal FairnessThe sustainability criterion suggests that, at a minimum, future generations should be left no worse off than current generations.3. Defining Intertemporal FairnessDo our institution provide adequate protection for future generations? Are all efficient allocations sustainable?4. Ar

10、e Efficient Allocation Fair?In the numerical example we have constructed, it certainly does not appear that particular efficient allocation satisfies the sustainable criterion because more resources are allocated to the first period than to the second.4. Are Efficient Allocation Fair?Although dynami

11、c efficient allocations do not automatically satisfy sustainability criteria, they can be perfectly consistent with sustainability, even in an economy relying heavily on depletable resources because it will always be possible to set aside sufficient net benefits accrued in the first period for those

12、 in the second period, so that those in the second period will be at least as well off as they would have been with any other extraction profile.5. Applying The Sustainability CriterionOne of the difficulties in assessing the fairness of intertemporal allocations using version of the sustainability

13、criterion is that it is so difficult to apply.5. Applying The Sustainability CriterionIs it possible to develop a version of the sustainability criterion that is more operational?Fortunately it is, thanks to what has e known as the “Hartwick Rule.”John Hartwick (1977) demonstrated that a constant le

14、vel of consumption could be maintained perpetually if all the scarcity rent were invested in capital.5. Applying The Sustainability CriterionTwo important insights flow from Hartwicks reinterpretation of the sustainability criterion.First, with this version it is possible to judge the sustainability

15、 of an allocation by examining whether or not the value of the total capital stock is nondeclining.Second, this analysis suggests the specific degree of sharing that would be necessary to produce a sustainable e, namely all scarcity rent must be invested.5. Applying The Sustainability CriterionHow d

16、o we apply Hartwick Rule to environment?In general, the Hartwick Rule suggests that the current generation has been given an endowment.Sustainable use of this endowment implies that we should keep the principal (the value of the endowment ) intact and live off only the flow of services provided.5. A

17、pplying The Sustainability CriterionWeak sustainability means that resource use by previous generations should not exceed a level that would prevent subsequent generations from achieving a level of well-being at least as great. One of the implications of this definition is that the value of the capi

18、tal stock (natural plus physical capital ) should not decline.5. Applying The Sustainability CriterionStrong sustainability means that the value of the remaining stock of natural capital should not decrease. This definition places special emphasis on preserving natural capital under the assumption t

19、hat natural and physical capital offer limited substitution possibilities.5. Applying The Sustainability CriterionEnvironmental sustainability means that the physical flows of individual resources should be maintained, not merely the value of the aggregate.6. Implications For Environmental PolicyIn

20、order to be useful guides to policy, our sustainability and efficiency criteria must be neither synonymous nor patible. Do these criteria meet that test?They do. Objectives & RequirementsGrasp the two-period model Understand the meaning of marginal user costUnderstand the impacts of discount rate on resource allocationUnderstand the meaning of sustainability, weak sustainability, strong sustainability and environmental sustainability Understand the relationship between efficient allocation and fairness DiscussionCompare two versions of