Accounting for Negative,Zero and Positive Willingness to Pay for Landscape Change in a National Park

In contingent valuation, despite the fact that many externalities manifest themselves as costs to some and benefits to others, most studies restrict willingness to pay to being non‐negative. In this paper, we investigate the impact of allowing for negative, zero and positive preferences for prospective changes in woodland cover in two UK national parks, the Lake District and the Trossachs. An extended spike model is used to accomplish this. The policy implications of not allowing for negative values in terms of aggregate benefits are also investigated, by comparing the extended spike model with a simple spike making use of only zero and positive bids, and a model which considers positive bids only. We find that ignoring negative values over‐states the aggregate benefits of a woodland planting project by up to 44%.     

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.     

经济发达地区耕地非市场价值及居民支付意愿研究——以南京市为例

研究目的：以南京市为例,研究耕地的非市场价值及城乡居民支付意愿的影响因素。研究方法：条件价值法,计量模型。研究结果：（1）南京市耕地的非市场价值为504087.92万元,单价为20760.59元/hm2;（2）57.76%市民和60.32%的农民家庭愿意为耕地非市场价值付费,支付意愿分别为208.33元/户•a和120.26元/户•a;（3）家庭收支水平、年龄、性别、受教育状况、对耕地非市场价值的认知等是影响城乡居民支付意愿的重要因素。研究结论：受家庭支付能力及其在耕地非市场价值方面受到教育的影响,城乡居民对耕地非市场价值的支付意愿并不高。     

The impact of deal‐proneness on WTP estimates in incentive‐aligned value elicitation methods

Even after controlling for hypothetical biases, some incentive‐aligned value elicitation methods still produce different willingness‐to‐pay (WTP) estimates. In this study, we compare WTP estimates from three incentive‐aligned value elicitation methods: real choice experiment (RCE), real double‐bounded dichotomous contingent valuation (RCVM), and Becker–DeGroot–Marschak auction (BDM). We find that participants’ aggressiveness in obtaining low prices (i.e., “deal‐proneness”) influences WTP estimates in the BDM auction, but not those elicited from the RCE and RCVM. The participants with higher levels of deal‐proneness tend to submit lower bids in the BDM auction. The discrepancies in WTP estimates between different incentive‐aligned procedures are narrower for participants with lower levels of deal‐proneness. Our results indicate that the bids in BDM auctions may be understated and the auction mechanism may induce the “gambling behavior” of people who are deal‐prone. That is, whether the BDM auction is truly incentive‐aligned is again called into question. We also discuss the practical implications for food retailers.     

Cattle Farmers’ Preferences for Disease‐Free Zones in Kenya: An application of the Choice Experiment Method

Management of livestock diseases is important in ensuring food safety to consumers in both domestic and export markets. Various measures are prescribed under the Sanitary and Phytosanitary Standards (SPS) agreement of the World Trade Organization. In order to prevent the spread of trans‐boundary cattle diseases, the SPS agreement recommends the establishment of Disease‐Free Zones (DFZs). These have been implemented successfully in some major beef‐exporting countries, but in Kenya are still at a pilot stage. To understand Kenyan farmers’ preferences on the type of DFZ that would be readily acceptable to them, a choice experiment was conducted using a D‐optimal design. Results show that farmers would be willing to pay to participate in a DFZ where: adequate training is provided on pasture development, record keeping and disease monitoring; market information is provided and sales contract opportunities are guaranteed; cattle are properly labelled for ease of identification; and some monetary compensation is provided in the event that cattle die due to severe disease outbreaks. Preferences for the DFZ attributes are shown to be heterogeneous across three cattle production systems. We also derive farmers’ preferences for various DFZ policy scenarios. The findings have important implications for policy on the design of DFZ programmes in Kenya and other countries that face similar cattle disease challenges.     

Consumer Acceptance of Second‐Generation GM Foods: The Case of Biofortified Cassava in the North‐east of Brazil

Biofortified staple foods are currently being developed to reduce problems of micronutrient malnutrition among the poor. This partly involves use of genetic modification. Yet, relatively little is known about consumer acceptance of such second‐generation genetically modified (GM) foods in developing countries. Here, we analyse consumer attitudes towards provitamin A GM cassava in the north‐east of Brazil. Based on stated preference data, mean willingness to pay is estimated at 60–70% above market prices for traditional cassava. This is higher than the results from similar studies in developed countries, which is plausible given that micronutrient malnutrition is more severe in developing countries. GM foods with enhanced nutritive attributes seem to be well received by poor consumers. However, the results also suggest that acceptance would be still higher if provitamin A were introduced to cassava through conventional breeding. Some policy implications are discussed.