Using Labels to Investigate Scope Effects in Stated Preference Methods

Insufficient sensitivity to scope (variations in the scale of the environmental good on offer) remains a major criticism of stated preference methods, and many studies fail a scope test of some sort. Across a range of existing explanations for insensitivity to scope (commodity mis-specification, embedding, warm glows) there seems to exist no clear conclusion on how to deal with the problem. This paper provides an alternative explanation for insufficient sensitivity to scope, based on re-definition of the determinants of value for environmental goods within an attributes-based choice model. In the proposed framework respondents’ Willingness To Pay need depend not only on physical characteristics of a good, but may also depend on the ‘label’ under which the environmental good is ‘sold’ in the hypothetical market. To investigate this problem, a Choice Experiment study of biodiversity was conducted. We find that controlling for the effects of a label—in this case, national park designation—leads to significant increase in the scope sensitivity of welfare measures.     

Valuing changes in forest biodiversity

The paper attempts to improve current understanding of the economic value of biodiversity. Instead of the prevailing approach of using only one indicator of biodiversity (typically, species richness) we provide evidence that it is possible to value changes in a number of attributes which describe complex characteristics of biodiversity, based on ecological knowledge. The attributes used include structural, species and functional diversity. The empirical application is a choice experiment study conducted in the Białowieża Forest, Poland: our study is therefore also one of the first to cast light on the value of biodiversity protection in Eastern Europe. Interestingly, respondents valued passive protection regimes resulting in preservation of natural ecological processes. In addition, the respondents seemed to be concerned with the means, and not only the results of protection programmes.     

The effect of decoupling on marginal agricultural systems: Implications for farm incomes,land use and upland ecology

In many parts of Europe, decades of production subsidies led to the steady intensification of agriculture in marginal areas. The recent decoupling of subsidies from production decisions means that the future of farming in these areas is uncertain. For example, in the uplands of the United Kingdom, an area important both for biodiversity conservation and ecosystem service provision, hill farmers steadily increased stocking densities in response to headage payments but must now reconfigure farm businesses to account for the shift to the Single Farm Payment scheme. We examined hill farming in the Peak District National Park as a case study into the future of marginal agriculture after decoupling. We surveyed 44 farm businesses and from this identified six representative farm types based on enterprise mix and land holdings. We developed linear programming models of production decisions for each farm type to examine the impacts of policy changes, comparing the effects of decoupling with and without agri-environment and hill farm support, and evaluating the effects of removal of the Single Farm Payment. The main effects of decoupling are to reduce stocking rates, and to change the mix of livestock activities. Agri-environmental schemes mediate the income losses from decoupling, and farmers are predicted to maximise take up of new Environmental Stewardship programmes, which have both positive and negative feedback effects on livestock numbers. Finally, removal of the Single Farm Payment leads to negative net farm incomes, and some land abandonment. These changes have important implications for ongoing debates about how ecological service flows can be maintained from upland areas, and how marginal upland farming communities can be sustained.     

Using Geographically Weighted Choice Models to Account for the Spatial Heterogeneity of Preferences

In this paper, we investigate the use of geographically weighted choice models for modelling spatially clustered preferences. We argue that this is a useful way of generating highly‐detailed spatial maps of willingness to pay for environmental conservation, given the costs of collecting data. The data used in this study come from a discrete choice experiment survey of public preferences for the implementation of a new national forest management and protection programme in Poland. We combine these with high‐resolution spatial data related to local forest characteristics. Using locally estimated discrete choice models we obtain location‐specific estimates of willingness to pay (WTP). Variation in these estimates is explained by characteristics of the forests close to where respondents live. These results are compared with those obtained from a more typical, two stage procedure which uses Bayesian posterior means of the mixed logit model random parameters to calculate location‐specific estimates of WTP. We find that there are indeed strong spatial patterns to the benefits of changes to the management to national forests. People living in areas with more species‐rich forests and those living nearer bigger areas of mixed forests have significantly different WTP values than those living in other locations. This kind of information potentially enables a better distributional analysis of the gains and losses from changes to natural resource management, and better targeting of investments in forest quality.     

A CONTINGENT VALUATION STUDY OF UNCERTAIN ENVIRONMENTAL GAINS

Acid deposition in a present and future cause of biodiversity losses in vulnerable upland areas of Scotland important for nature conservation. However, the exact nature of damages under the status quo, and both the timing and extent of recovery of upland ecosystems if deposition is reduced, are subject to uncertainty. this uncertainty complicates damages cost estimation. In this paper, we have explored the use of CVM to measure the willingness to pay (WTP) of the Scottish population for uncertain recovery/damage scenarios from reduced acid rain deposition. An optimally-designed referendum format was used utilising the distribution of open-ended bids from a pilot study to determine bid amounts and sampling size for each bid amount. Eight explanatory variables, including future damage level were selected in a non-linear step-wise regression analysis. Average household WTP for abatement of acid rain was £247 and £351 per year when faced with low and high future damage levels respectively. Recovery level and recovery time did not significantly influence WTP. When faced with risky outcomes regarding future damage and recovery level, respondent were found to be risk averse to both environmental gains and losses.     

Macroeconomic Measures of 'Sustainability'

This paper reviews the policy need for indicators of 'sustainable development', and the impetus behind recent moves to establish official indicators. The range of indicators available from current economic theory is then examined. These measures may be divided into those based on flows and those based on stocks. Flow-based measures are essentially attempts to adjust Net National Product to transform it into an indicator of sustainability. Stock-based measures revolve around the concept of the natural and man-made capital stocks. We also consider the idea of Safe Minimum Standards as a sustainability indicator. The paper concludes that no currently-available single measure of sustainability is likely to be adequate.     

How accountability pressure on failing schools affects student achievement

Although an emerging body of evidence has shown that the threat of sanctions on low-performing schools can raise student test scores in the short run, the extent to which these test score improvements are due to schools' manipulation of the accountability system has remained uncertain. In this paper, I provide two new strands of evidence to evaluate the relative importance of educational reforms and gaming behavior in generating test score gains by threatened schools. First, using a regression discontinuity design that exploits Florida's system of imposing sanction threats on the basis of a cutoff level of performance, I estimate medium-run effects on student test scores from having attended a threatened elementary school. Threat-induced math improvements from elementary school largely persist at least through the first 1 to 2 years of middle school, while evidence for persistence of reading improvements is less consistent. Second, I analyze the effects of sanction threats on various features of educational production, and I find that sanction threats raise school spending on instructional technology, curricular development, and teacher training. Both strands of evidence are consistent with a predominant role for educational reforms in generating test score gains by threatened schools.     

A Conditional Approach to Measure Mortality Reductions Due to Cancer Screening

The prevailing lack of consensus about the comparative harms and benefits of cancer screening stems, in part, from the inappropriate calculations of the expected mortality impact of a sustained screening programme. There is an inherent, and often substantial, time lag from the time of screening until the resulting mortality reductions begin, reach their maximum and ultimately end. However, the cumulative mortality reduction reported in a randomised screening trial is typically calculated over an arbitrarily defined follow‐up period, including follow‐up time where the mortality impact is yet to realise or where it has already been exhausted. Because of this, the cumulative reduction cannot be used for projecting the mortality impact expected from a sustained screening programme. For this purpose, we propose a new measure, the time‐specific probability of being helped by screening, given that the cancer would have proven fatal otherwise. This can be decomposed into round‐specific impacts, which in turn can be parametrised and estimated from the trial data. This represents a major shift in quantifying the benefits due to a sustained screening programme, based on statistical evidence extracted from existing trial data. We illustrate our approach using data from screening trials in lung and colorectal cancers.     

Estimating the benefits of water quality improvements under the Water Framework Directive: are benefits transferable?

The Water Framework Directive sets an objective of ‘GoodEcological Status’ for water bodies across the EU. Non-pointpollution from agriculture is a major reason for the failureof rivers in the UK to meet this target. In this paper, we usechoice experiment methodology to test the transferability ofbenefit estimates of water quality improvements for two smallcatchments where agricultural-source non-point pollution andirrigation water abstraction are the main threats to ecologicalstatus. We also investigate the most appropriate techniquesto apply to transfer testing, including allowing for correlationbetween preferences for environmental attributes, and testingfor acceptable differences between transferred and originalvalues.