Stakeholder Willingness to Pay for Watershed Restoration in Rural Bolivia1

Abstract: Two CVM surveys were administered to 211 urban households and 188 rural farmer‐irrigators in the Comarapa watershed in Bolivia, South America, to estimate stakeholder willingness to pay (WTP) for a proposed upper watershed restoration program. Mean monthly household WTP to improve drinking water was $1.95 (65% of current charges), while mean annual WTP among farmer‐irrigators to improve irrigation water was $17 per hectare (34% of current costs). Aggregated to the entire population of households and farmer‐irrigators total WTP is $77,400 per year, which is 77% of the minimum cost to implement a watershed restoration program.     

Is there a commercially viable market for crop insurance in rural Bangladesh?

The study aims to assess the commercial viability of a potential crop insurance market in Bangladesh. In a large scale household survey, agricultural farm households were asked for their preferences for a hypothetical crop insurance scheme using double bounded (DB) contingent valuation (CV) method. Both revenue and production cost based indemnity payment approaches were applied to assess the commercial viability of a crop insurance program assuming a partner-agent (PA) model of insurance supply. Crop insurance is found marginally commercially viable in riverine flood plain areas. The expected indemnity payable consistently exceeds the expected insurance premium receivable by the insurer for the households living in wetland basin and coastal floodplain. We conclude that a uniform structure of crop insurance market does not exist in Bangladesh. The nature of the disaster risks faced by the farm households and the socio-economic characteristics of the rural farm communities need to be taken into careful consideration while designing such an insurance scheme.

牛顿（切线）法求极值在估算水质模型参数中的应用

文章根据水环境容量计算条件,建立了适用于中小河河流一维忽略污染物沉降扣弥散作用的数学模型。建立了由实测值与拱型计算值之差的平方构成的目标函数。通过目标函数,把水质模型参数的估算转变成一个单变量函数求极值的问题。本文采用牛顿（切线）法求极值和计算机技术解决了这个单变量函数求极值问题,解决了在有多排污口存在的河段估算污染物衰减系数K值的难题。该办法的使用提高了水环境容量计算的可靠性和准确度。     

基于双边界二分式CVM法对上海池塘养殖环境成本的实证研究

为正确认识池塘养殖的正、负生态服务价值,避免养殖生产过程中存在的盲目和短视,促进水产养殖经济与环境和谐发展,对上海环淀山湖地区的养殖池塘环境进行随机抽样调查,获得了当地居民对于环境污染的受偿意愿(WTA)水平。利用STATA10.0定量分析池塘养殖环境成本,并用双边界二分式CVM法,估算得到该区域2010年池塘养殖环境成本约为1 982.26万元,约合5 105元/hm~2。研究表明,年龄、家庭收入、受教育程度等因素对居民的受偿意愿影响显著,但具体影响力方向还有待进一步探讨;政府制定生态补偿政策时应将各相关因素纳入综合考虑。     

The value of disappearing beaches: A hedonic pricing model with endogenous beach width

Beach nourishment is a policy used to rebuild eroding beaches with sand dredged from other locations. Previous studies indicate that beach width positively affects coastal property values, but these studies ignore the dynamic features of beaches and the feedback that nourishment has on shoreline retreat. We correct for the resulting attenuation and endogeneity bias in a hedonic property value model by instrumenting for beach width using spatially varying coastal geological features. We find that the beach width coefficient is nearly five times larger than the OLS estimate, suggesting that beach width is a much larger portion of property value than previously thought. We use the empirical results to parameterize a dynamic optimization model of beach nourishment decisions and show that the predicted interval between nourishment projects is closer to what we observe in the data when we use the estimate from the instrumental variables model rather than OLS. As coastal communities adapt to climate change, we find that the long-term net value of coastal residential property can fall by as much as 52% when erosion rate triples and cost of nourishment sand quadruples.     

Combining Stated Preference and Revealed Preference Methods for the Valuation of Non-market Goods

Abstract

In this paper, we introduce the combining stated preference and revealed preference methods which is the state-ofthe- art method for the valuation of non-market goods. Revealed preference methods and stated preference (SP) methods have both been applied by economists in valuing non-market goods; however both methods have inherent weaknesses. In order to exploit the strengths of the various approaches while minimizing their weaknesses, combining the two methods has become an important methodological option. Up to now, a growing number of literatures of studying combing the two types of data have evolved, and researchers developed three types of models to estimate combining revealed preference and stated preference data in academic fields: discrete choice model, continuous choice model and mixed choice model. Combining stated and revealed preference methods have been developed fast especially in the transport study field in which ideas could also be leant for environmental economic studies.     

Valuing nature-based recreation in public natural areas of the Apalachicola River region, Florida

As more people visit natural areas for tourism and recreation purposes, it is becoming increasingly important to understand the value they place on these natural resources. Specifically, tourists to Florida have been increasingly interested in visiting natural areas, forests, parks, and preserves-highlighting the importance of this new and growing phenomenon. We analyze visitors' demand for nature-based recreation in the Apalachicola River region of Florida using the travel cost method. The results from a count data regression model reveal that on average visitors would pay 74.18 dollars per visit-day for nature-based recreation resulting in a total economic value of 484.56 million dollars attributable to nature-based recreation in the Apalachicola River region. Results of this study provide useful information for natural resources management in the region and a rationale to preserve Florida's unique ecosystems.     

Intelligent Databases Assist Transparent and Sound Economic Valuation of Ecosystem Services

Assessment and economic valuation of services provided by ecosystems to humans has become a crucial phase in environmental management and policy-making. As primary valuation studies are out of the reach of many institutions, secondary valuation or benefit transfer, where the results of previous studies are transferred to the geographical, environmental, social, and economic context of interest, is becoming increasingly common. This has brought to light the importance of environmental valuation databases, which provide reliable valuation data to inform secondary valuation with enough detail to enable the transfer of values across contexts. This paper describes the role of next-generation, intelligent databases (IDBs) in assisting the activity of valuation. Such databases employ artificial intelligence to inform the transfer of values across contexts, enforcing comparability of values and allowing users to generate custom valuation portfolios that synthesize previous studies and provide aggregated value estimates to use as a base for secondary valuation. After a general introduction, we introduce the Ecosystem Services Database, the first IDB for environmental valuation to be made available to the public, describe its functionalities and the lessons learned from its usage, and outline the remaining needs and expected future developments in the field.     

居民为改善北京市大气环境质量的支付意愿研究

用意愿调查价值评估法分析了北京市居民为改善大气环境质量的支付意愿 ,评估大气质量改善的价值 ,并对这一方法在我国的应用进行探讨。结果显示 ,研究范围内的居民为 5年内降低目前大气污染物质浓度的 5 0 %而支付费用的平均支付意愿是 143元 /户·年 (1999年元 ) ,该区域内居民总的支付意愿是 3 .36亿元 /年 (1999年元 ) ,被调查者的家庭收入、教育水平、家庭人口数和年龄等社会经济变量对支付意愿有显著影响。最后 ,对意愿调查价值评估法在我国应用时存在的问题进行了初步探讨     

生态系统健康评价及其问题

讨论了生态系统健康的概念及内涵，指出了生态系统健康评价中存在的主要问题，最后对今后生态系统健康评价的研究方向作了展望。