Environmental Cost-Benefit Analysis
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ANRV357-EG33-14 ARI 15 September 2008 16:26 ANNUAL Environmental Cost-Benefit REVIEWS Further Click here for quick links to Annual Reviews content online, Analysis including: • Other articles in this volume • Top cited articles Giles Atkinson and Susana Mourato • Top downloaded articles • Our comprehensive search Department of Geography and Environment and Grantham Research Institute on Climate Change and the Environment, London School of Economics and Political Science, London, WC2A 2AE, United Kingdom, email: [email protected] Annu. Rev. Environ. Resour. 2008. 33:317–44 Key Words First published online as a Review in Advance on environmental valuation, equity, uncertainty August 21, 2008 The Annual Review of Environment and Resources Abstract is online at environ.annualreviews.org Environmental cost-benefit analysis, or CBA, refers to the economic This article’s doi: appraisal of policies and projects that have the deliberate aim of im- 10.1146/annurev.environ.33.020107.112927 proving the provision of environmental services or actions that might af- Copyright c 2008 by Annual Reviews. fect (sometimes adversely) the environment as an indirect consequence. All rights reserved Vital advances have arisen in response to the challenges that environ- 1543-5938/08/1121-0317$20.00 mental problems and environmental policy pose for CBA. In this arti- cle, we review a number of these developments. Perhaps most notably this includes continuing progress in techniques to value environmen- tal changes. Growing experience of these methods has resulted in, on by London School of Economics and Political Science on 01/07/14. For personal use only. Annu. Rev. Environ. Resourc. 2008.33:317-344. Downloaded from www.annualreviews.org the one hand, ever greater sophistication in application and, on the other hand, scrutiny regarding their validity and reliability. Distribu- tional concerns have led to a renewal of interest in how appraisals might throw light on questions about equity as well as efficiency, and there have been substantial new insights for discounting costs and benefits in the far-off future. Uncertainty about what is lost when environmental assets are degraded or depleted has resulted in a number of distinct proposals although precaution is the watchword in each. Just as importantly, there is a need to understand when CBA is used in practice and why environ- mental decisions are often made in a manner apparently inconsistent with cost-benefit thinking. 317 ANRV357-EG33-14 ARI 15 September 2008 16:26 developments primarily in environmental eco- Contents nomics (but also in other fields of economic inquiry such as health economics). It is the ob- 1. INTRODUCTION ................ 318 jective of this article to review the most impor- 2. ENVIRONMENTAL tant of these recent developments. VALUATION ..................... 318 In doing so, we identify what justly can be 2.1. Stated Preference Methods ..... 319 considered to be the core activity in environ- 2.2. Revealed Preference Methods . 324 mental CBA: the estimation of monetary val- 2.3. Benefits Transfer............... 326 ues for environmental changes, environmental 3. EQUITY AND CBA ............... 328 valuation. This has given rise to a prolifera- 4. DISCOUNTING tion of methods that have sought to uncover, AND THE FUTURE ............. 330 in a variety of ways, the value of environmental 5. UNCERTAINTY impacts (and nonmarket impacts more gener- AND IRREVERSIBILITY......... 332 ally). As we discuss, critical scrutiny of these 6. CBA, ITS CRITICS, methods has also been prominent. Although AND THE REAL WORLD ....... 333 developments in techniques of nonmarket val- 7. CONCLUSIONS .................. 336 uation have been a defining feature of envi- ronmental CBA, a broader array of evolving issues has also come to the fore in extend- 1. INTRODUCTION ing economic appraisal to contemporary en- vironmental policy challenges, perhaps most Although the principles of cost-benefit analy- notably climate change and biodiversity loss. sis (CBA) remain largely the same, the prac- Some of these issues can be summarized as RP: revealed tice of carrying out appraisals has undergone a stemming from distributional concerns with re- preference 1 transformation over the past two or so decades. gards to how human well-being and wealth are SP: stated preference Nowhere is this more the case than for en- distributed across generations as well as within vironmental applications: that is, cost-benefit generations: respectively inter- and intragener- appraisals of policies and projects that have ational equity. Other insights have emerged in the deliberate aim of improving the provision response to reflections on whether the extent of environmental services or actions that af- and nature of the uncertainty and irreversibility fect (sometimes adversely) the environment as that characterize certain environmental prob- an indirect consequence. Current best practice lems might require that decision making needs in environmental cost-benefit analysis reflects, in to be weighted more heavily in favor of precau- its turn, an array of conceptual and empirical tion. Finally, there are important issues of how CBA operates in the real world and in relation to its critiques. Just as important are questions 1 by London School of Economics and Political Science on 01/07/14. For personal use only. There is an extensive academic literature on CBA, some of Annu. Rev. Environ. Resourc. 2008.33:317-344. Downloaded from www.annualreviews.org of political economy: What reasons explain why which may not use the term cost-benefit analysis but instead refers to benefit-cost analysis, policy evaluation, or project actual policy design diverges from the optimal appraisal. Numerous texts and manuals have appeared, many design of those policies according to CBA? covering the general field of CBA [e.g., Sugden & Williams (1); Just et al. (2); Boardman et al. (3)]. Other contribu- tions have covered detailed procedures for estimating shadow prices (i.e., the true social value of costs of benefits as opposed 2. ENVIRONMENTAL to the distorted market prices we might observe in reality), VALUATION especially in developing countries [e.g., Ray (4); Londero (5)]. These texts remain highly relevant in environmental Two main approaches have been developed contexts where, for example, policy distortions remain sub- to place an economic value on nonmarket stantial, such as perhaps in the evaluation of biofuels. More goods and services: revealed preference (RP) recently, texts have appeared specifically in the environmen- tal context [e.g., Johansson (6); Hanley & Spash (7); Pearce and stated preference (SP) methods. There et al. (8)]. are many possible uses for such information. 318 Atkinson · Mourato ANRV357-EG33-14 ARI 15 September 2008 16:26 Within the context of CBA, the objective is to asked to express their maximum willingness generate original (or primary) data on the total to pay (WTP) or minimum willingness to ac- economic value that the public places on envi- cept (WTA) compensation for a hypothetical CV: contingent ronmental changes that arise as a result of some change in the level of provision of the good. valuation policy proposal.2 A complementary approach, The method can be used to estimate all the ben- WTA: willingness to that of benefits (or value) transfer, draws on efits (use and nonuse) associated with a change accept the accumulated findings within such valuation in the level of provision of a good or service. CV WTP: willingness to studies conducted to date and so applies exist- is firmly rooted in the economic theory of indi- pay ing monetary values (or secondary data perhaps vidual choice. For thorough reviews of the CV after some adjustment) to new policy contexts. method see Mitchell & Carson (10), Bateman The techniques and recent developments are et al. (9), Champ et al. (11), and Alberini & Kahn discussed in the sections that follow. (12). This asserts that elicited WTP or WTA values are monetary measures of respondents’ preferences, corresponding to Hicksian welfare 2.1. Stated Preference Methods measures. That is, for a proposal that results in Stated preference (SP) methods is an umbrella an environmental improvement, the change in term under which are found a range of survey- well-being that an individual enjoys can be mea- based methods that use constructed or hypo- sured by his or her WTP for, or his or her WTA thetical markets to elicit preferences for spec- compensation to forego, that improvement. For ified policy changes [Bateman et al. (9)]. By an environmental deterioration, the change in far the most widely applied SP technique is well-being is the WTP to avoid that outcome the contingent valuation (CV) method. Over or WTA compensation to tolerate it. Choosing the past 40 years, this technique has been in- between WTP and WTA, in a given context, ar- creasingly used by academics and policy makers guably remains a contentious issue, although in owing to its flexibility and ability to estimate the large part the choice is determined by whether economic value of environmental goods that people affected by a policy have a property right are not traded in markets. Using an appro- to the current or the new level of provision priately designed questionnaire, a hypotheti- of the good in question. In addition, CV (and cal (or contingent) market is described where SP approaches more generally) combines these the good in question (which might be an im- economic precepts with insights from psychol- provement in water quality, reduction in a risk ogy and survey research. to human health, or protection of an ecosys- The CV method has been extensively ap- tem) can be traded. This contingent market plied in both developed and developing coun- defines the good itself, the institutional con- tries and the range of environmental issues text in which it would be provided, and the addressed is wide: water quality, outdoor way it would be financed. Respondents are then recreation, species preservation, forest protec- by London School of Economics and Political Science on 01/07/14.