支付意愿引导技术:支付卡式、单边界二分式和双边界二分式的比较——以三江平原生态旅游水资源的非使用价值为例

条件价值评估法(CVM)是评估资源、环境物品及服务价值最广泛的方法.支付意愿(WTP)的引导技术是CVM研究的重要手段.对WTP引导技术的研究是提高CVM评价可靠性和有效性的重要途径.本文以三江平原生态旅游水资源的非使用价值为评价对象,分别运用支付卡式、单边界二分式和双边界二分式3种WTP引导技术对其进行综合评价,并对3种引导方式进行对比分析.结果表明: 支付卡式、单边界二分式及双边界二分式中的社会经济属性对支付意愿的影响关系一致,其中,变量投标值、年龄、受教育程度、年收入以及关心程度对支付意愿的影响显著,变量性别和职业对支付意愿的影响不显著.支付卡式的WTP为每人112.46元,其次是单边界二分式(136.15元),双边界二分式问卷的WTP为每人168.74元.综合考虑调查对象的性质、调查成本以及统计技术等,双边界二分式的结果(47.86×10⁸元·a^-1)最符合实际,可作为三江平原生态旅游水资源的非使用经济价值.不同WTP引导方式对支付意愿的影响很大,为提高问卷有效性,合理选择调查问卷类型至关重要.
     

锡林郭勒生物圈保护区草原生态系统服务间接价值动态评估

草地是我国面积最大的陆地生态系统类型,对于维持我国北方的生态安全具有重要价值。北方草原的大面积退化已引起人们的极大关注。以内蒙古锡林郭勒生物圈保护区为研究区域．利用2个年份的遥感数据,结合地面样方调查,在GIS的支持下,绘制出草原退化空间分布图。选取草原生态系统在控制土壤侵蚀、减少土壤肥力流失、营养物质循环、CO2储存和O2释放方面的功能指标,对草原生态系统服务间接价值进行了动态评估。1985年和1999年草原退化面积分别为7190．9和7689．3km^2,占研究区总面积的67．19％和71．86％。2个年份草原生态系统间接服务总价值分别为28．24和26．75亿元．下降了5．28％,单位面积间接服务价值分别为2990和2830元。下降了5．35％。人类的过度放牧是导致草原大面积退化,生态系统功能降低和服务价值下降的主要原因。     

Contrasting patterns of phenotypic variation linked to chromosomal inversions in native and colonizing populations of Drosophila subobscura

In fewer than two decades after invading the Americas, the fly Drosophila subobscura evolved latitudinal clines for chromosomal inversion frequencies and wing size that are parallel to the long‐standing ones in native Palearctic populations. By sharp contrast, wing shape clines also evolved in the New World, but the relationship with latitude was opposite to that in the Old World. Previous work has suggested that wing trait differences among individuals are partially due to the association between chromosomal inversions and particular alleles which influence the trait under consideration. Furthermore, it is well documented that a few number of effective individuals founded the New World populations, which might have modified the biometrical effect of inversions on quantitative traits. Here we evaluate the relative contribution of chromosomal inversion clines in shaping the parallel clines in wing size and contrasting clines in wing shape in native and colonizing populations of the species. Our results reveal that inversion‐size and inversion‐shape associations in native and colonizing (South America) populations are generally different, probably due to the bottleneck effect. Contingent, unpredictable evolution was suggested as an explanation for the different details involved in the otherwise parallel wing size clines between Old and New World populations of D. subobscura. We challenge this assertion and conclude that contrasting wing shape clines came out as a correlated response of inversion clines that might have been predicted considering the genetic background of colonizers.     

A note on communicating environmental change for non-market valuation

Communicating change in environmental condition is a critical component of non-market valuation studies. However, the underlying assumptions and implications associated with alternative ways of expressing change in environmental condition for surveys are rarely discussed in the literature. Our review found no cases where alternative formulations were both discussed and tested. In this note we report on our multi-disciplinary analysis of how best to express such change. We interrogate the meaning of, and inferences from, four formulations for quantitative expressions, or metrics, of environmental indicators that are used in the field of ecology and we then evaluate their usefulness in non-market valuation. The assumptions and limitations of each formulation are discussed using seven hypothetical cases of change in environmental condition. We show that formulations for expressing change can be grouped based on two inherent philosophies potentially held by people when they consider their preferences for environmental changes: ‘more is better philosophy’ and ‘restoration philosophy’. We contend that, without careful consideration of which philosophy people may apply, it is possible to inadvertently bias respondent choices when a particular formulation is used in a valuation study. If this happens, resulting value estimates will be a poor reflection of what researchers seek. An alternative approach that does not presuppose a philosophy but instead helps reveal a respondent’s philosophy, is proposed.     

Assessing recreational benefits as an economic indicator for an industrial harbour report card

Industrial harbours are a complex interface between environmental, economic and social systems. Trying to manage the social and economic needs of the community while maintaining the integrity of environmental ecosystems is complicated, as is the identification and evaluation of the various factors that underpin the drivers of economic, community and resource condition. An increasingly popular strategy to deal with the identification and evaluation challenges in complex human-environmental systems is to use a report card system which can be used as a summary assessment tool to monitor the health of aquatic ecosystems. To date though these have largely focused on environmental factors, and it is only very recently that attempts are being made to include social, cultural and economic indicators. There has been limited consensus in the selection of social and economic indicators applied in different aquatic report cards but as recreation is such an important activity, typically some measure of recreation benefit is included. However, there has been no commonality in the measures applied to assess its performance as an economic indicator.This paper is focused on the assessment of recreational benefits as an indicator of economic value in the report card for Gladstone Harbour in Queensland, Australia. It is the first aquatic health report card to include an assessment of the nonmarket value of recreation which makes it a more comprehensive indicator of economic value compared to other report cards based on measures of employment, participation or expenditure. There have now been three consecutive years of reporting (2014–2016) of the Gladstone Harbour report card, and the results indicate that the recreation index appears to be effective in monitoring changes over time.     

时间选择性注意的认知神经机制

时间选择性注意是注意研究中开展较晚的一个领域,它是指通过有效的提示,将注意资源导向与即将到来的事件相关的时间点或时间窗的过程．回顾了时间选择性注意的行为及其认知神经机制的研究,并在与空间选择性注意比较的基础上,对热点问题和未来的研究趋势进行了分析．     

Evidence of separate subgroups of juvenile southern bluefin tuna

Archival tagging studies of southern bluefin tuna (SBT, Thunnus maccoyii) have revealed that juveniles residing in the Great Australian Bight (GAB) over the austral summer undertake seasonal cyclic migrations to the southeast Indian Ocean and the Tasman Sea during winter. However, there remains disagreement about the extent of mixing between juvenile SBT regularly caught by longline fleets south of Africa and those observed in the GAB. Some researchers have argued that archival tag recoveries indicate most juveniles reside in the GAB over the austral summer. Others have suggested that recoveries of conventional and archival tags are better explained by a juvenile population consisting of separate groups on the eastern and western sides of the Indian Ocean with limited intermixing. We present analyses of catch and tag recovery data and re‐examine archival tagging studies. The evidence provided strongly favors the hypothesis of separate juvenile subgroups, or contingents, with limited intermixing. We draw some tentative conclusions about the nature of the putative contingents and discuss some implications of these findings for the interpretation of existing datasets and future research priorities. We also provide the first evidence that the migration choices of juveniles that summer in the GAB are influenced by fidelity to winter feeding grounds and suggest this helps explain the collapse of the surface fishery off New South Wales in the 1980s.     

Contingent valuation analysis of willingness to pay to reduce childhood obesity

Several recent surveys have asked Americans whether they support policies to reduce childhood obesity. There is reason for skepticism of such surveys because people are not confronted with the tax costs of such policies when they are asked whether they support them. This paper uses contingent valuation (CV), a method frequently used to estimate people's willingness to pay (WTP) for goods or services not transacted in markets, applied to unique survey data from New York State to estimate the willingness to pay to reduce childhood obesity. The willingness to pay data correlate in predictable ways with respondent characteristics. The mean WTP for a 50% reduction in childhood obesity is $46.41 (95% CI: $33.45, $59.15), which implies a total WTP by New York State residents of $690.6 million (95% CI: $497.7, $880.15), which is less than that implied by previous surveys that did not use CV methods but greater than current spending on policies to reduce childhood obesity and greater than the estimated savings in external costs. The findings provide policymakers with useful information about taxpayers' support for, and preferred budget for, anti-obesity policies.     

On the pathophysiology of migraine--links for "empirically based treatment" with neurofeedback

Psychophysiological data support the concept that migraine is the result of cortical hypersensitivity, hyperactivity, and a lack of habituation. There is evidence that this is a brain-stem related information processing dysfunction. This cortical activity reflects a periodicity between 2 migraine attacks and it may be due to endogenous or exogenous factors. In the few days preceding the next attack slow cortical potentials are highest and habituation delay experimentally recorded during contingent negative variation is at a maximum. These striking features of slow cortical potentials are predictors of the next attack. The pronounced negativity can be fed back to the patient. The data support the hypothesis that a change in amplitudes of slow cortical potentials is caused by altered habituation during the recording session. This kind of neurofeedback can be characterized as empirically based because it improves habituation and it proves to be clinically efficient.