Including risk in stated-preference economic valuations: Experiments on choices for marine recreation

Stated-preference surveys for the economic valuation of environmental resources typically assume no uncertainty in the hypothetical valuation scenarios. However, the outcomes of environmental policies are uncertain. We explored the effects of including information on probabilities of attribute improvement and provision in choice experiments. Our results suggest that stating explicitly a high probability for the occurrence of the valuation scenario can improve the goodness of fit of choice models and the consistency of choices. As the general public becomes more aware of the uncertainty of environmental outcomes under global change, omitting information on scenario risk may contribute to hypothetical bias and impair the validity of stated-preference valuations.     

秦皇岛探测环境变化对气象要素的影响

为分析秦皇岛地面气象探测环境变化对气象要素的影响,采用距平百分率和线性倾向估计及趋势系数等方法,对秦皇岛气象站（54449）新、旧站址搬迁前后1989—1998、1999—2008年各10年,与没有迁站的昌黎站做同期资料比较,结果表明：秦皇岛探测环境变化对气象要素有显著影响：年平均气温、年极端气温较迁站前显著下降,相对湿度增大,日照时数明显减少,雾日增多。指出气象要素变化除具有随时间变化的共同差异外,主要受探测环境变化的影响。     

抓住机遇,建设新世纪专群结合的地震监测预报系统

建设专家为主、专群结合的地震监测预报体系是当前防震减灾的重点工作之一。通过回顾浙江省“九五”期间建设地震监测系统的实践 ,认为在当前科技水平和管理体制下 ,专群结合是建设好现代化地震监测预报系统的重要保证。省局必须正确处理好省级以下地震部门工作中的几个问题 ,发挥专业队伍在监测预报体系中的主导作用 ,才能做好新时期的地震监测预报工作。     

数字地震仪器的管理维护及在观测应用中的几点体会

“九五”期间 ,我国建立了数字地震观测台网。在模拟地震观测向数字地震观测的转变中 ,从仪器的管理维护到地震的观测分析有许多地方需要不断地改进与完善。我台用数字地震仪观测一年多来 ,积累了一定经验 ,摸索了一些排除故障解决问题的方法。总结于此 ,以便于借鉴。     

Assessment of Alternative Methods for Statistically Downscaling Daily GCM Precipitation Outputs to Simulate Regional Streamflow

This study applied three statistical downscaling methods: (1) bias correction and spatial disaggregation at daily time scale (BCSD_daily); (2) a modified version of BCSD which reverses the order of spatial disaggregation and bias correction (SDBC), and (3) the bias correction and stochastic analog method (BCSA) to downscale general circulation model daily precipitation outputs to the subbasin scale for west‐central Florida. Each downscaled climate input dataset was then used in an integrated hydrologic model to examine differences in ability to simulate retrospective streamflow characteristics. Results showed the BCSD_daily method consistently underestimated mean streamflow because the highly spatially correlated small precipitation events produced by this method resulted in overestimation of evapotranspiration. Highly spatially correlated large precipitation events produced by the SDBC method resulted in overestimation of the standard deviation of wet season daily streamflow and the magnitude/frequency of high streamflow events. BCSA showed better performance than the other methods in reproducing spatiotemporal statistics of daily precipitation and streamflow. This study demonstrated differences in statistical downscaling techniques propagate into significant differences in streamflow predictions, and underscores the need to carefully select a downscaling method that reproduces precipitation characteristics important for the hydrologic system under consideration.     

Use of opportunistic sightings and expert knowledge to predict and compare Whooping Crane stopover habitat

Predicting a species’ distribution can be helpful for evaluating management actions such as critical habitat designations under the U.S. Endangered Species Act or habitat acquisition and rehabilitation. Whooping Cranes (Grus americana) are one of the rarest birds in the world, and conservation and management of habitat is required to ensure their survival. We developed a species distribution model (SDM) that could be used to inform habitat management actions for Whooping Cranes within the state of Nebraska (U.S.A.). We collated 407 opportunistic Whooping Crane group records reported from 1988 to 2012. Most records of Whooping Cranes were contributed by the public; therefore, developing an SDM that accounted for sampling bias was essential because observations at some migration stopover locations may be under represented. An auxiliary data set, required to explore the influence of sampling bias, was derived with expert elicitation. Using our SDM, we compared an intensively managed area in the Central Platte River Valley with the Niobrara National Scenic River in northern Nebraska. Our results suggest, during the peak of migration, Whooping Crane abundance was 262.2 (90% CI 40.2?3144.2) times higher per unit area in the Central Platte River Valley relative to the Niobrara National Scenic River. Although we compared only 2 areas, our model could be used to evaluate any region within the state of Nebraska. Furthermore, our expert‐informed modeling approach could be applied to opportunistic presence‐only data when sampling bias is a concern and expert knowledge is available.     

Myths and assumptions about human-wildlife conflict and coexistence

Recent extinctions often resulted from humans retaliating against wildlife that threatened people's interests or were perceived to threaten current or future interests. Today's subfield of human-wildlife conflict and coexistence (HWCC) grew out of an original anthropocentric concern with such real or perceived threats and then, starting in the mid-1990s, with protecting valued species from people. Recent work in ethics and law has shifted priorities toward coexistence between people and wild animals. To spur scientific progress and more effective practice, we examined 4 widespread assumptions about HWCC that need to be tested rigorously: scientists are neutral and objective about HWCC; current participatory, consensus-based decisions provide just and fair means to overcome challenges in HWCC; wildlife threats to human interests are getting worse; and wildlife damage to human interests is additive to other sources of damage. The first 2 assumptions are clearly testable, but if they are entangled can become a wicked problem and may need debunking as myths if they cannot be disentangled. Some assumptions have seldom or never been tested and those that have been tested appear dubious, yet the use of the assumptions continues in the practice and scholarship of HWCC. We call for tests of assumptions and debunking of myths in the scholarship of HWCC. Adherence to the principles of scientific integrity and application of standards of evidence can help advance our call. We also call for practitioners and interest groups to improve the constitutive process prior to decision making about wildlife. We predict these steps will hasten scientific progress toward evidence-based interventions and improve the fairness, ethics, and legality of coexistence strategies.     

The accident-exposure association: self-reported versus recorded collisions

Problem

It has been claimed that exposure to risk of road traffic accidents (usually conceptualized as mileage) is curvilinearly associated with crashes (i.e., the increase in number of crashes decreases with increased mileage). However, this effect has been criticized as mainly an artifact of self-reported data.

Method

To test the proposition that self-reported accidents create part of the curvilinearity in data by under-reporting by high-accident drivers, self-reported and recorded collisions were plotted against hours of driving for bus drivers.

Results

It was found that the recorded data differed from self-reported information at the high end of exposure, and had a more linear association with the exposure measure as compared to the self-reported data, thus supporting the hypothesis.

Discussion

Part of the previously reported curvilinearity between accidents and exposure is apparently due to biased methods. Also, the interpretation of curvilinearity as an effect of exposure upon accidents was criticized as unfounded, as the causality may just as well go the other way. Impact on industry: The question of how exposure associates with crash involvement is far from resolved, and everyone who uses an exposure metric (mileage, time, induced) should be careful to investigate the exact properties of their variable before using it.     

Perceptions of personal vulnerability to workplace hazards in the Australian construction industry

Introduction

The importance of risk perception for workplace safety has been highlighted by the inclusion of risk appraisals in contemporary models of precautionary behavior at work. Optimism bias is the tendency to think that negative events are less likely to happen to oneself than to the average person, and is proposed to be related to the reduced use of precautions.

Method

Building on studies of optimism bias for workplace hazards using samples with heterogenous risk profiles, the current study aimed to investigate whether optimism bias is present in a sample of workers exposed to similar workplace hazards. 175 Australian construction workers completed a brief survey that asked them to rate the likelihood of common construction industry hazards occurring to them and to the average worker of the same age doing the same job. Significant levels of optimism bias were found for many hazards (including being electrocuted, being trapped in a confined space, falling from heights, and causing someone else to have an injury).

Results

Optimism bias was not related to perceived controllability, contrary to findings in other domains, yet consistent with findings of optimism bias for workplace hazards. Optimism bias was not found to be related to a reduction in safe work behaviors, though this may be due to difficulties in measuring safe or precautionary behavior, such as social desirability.

Impact on industry

That most workers think that hazards are less likely to happen to them than to the average worker presents a significant problem because it may ameliorate the efficacy of safety programs, yet constitutes a largely unexplored opportunity for improving workplace safety performance.     

基于卫星和地面观测的2013年以来我国臭氧时空分布及变化特征

采用卫星和地面观测臭氧（O₃）浓度,分析2013年以来我国O₃的时空分布和年际变化特征.卫星观测对流层O₃总量和地面观测O₃浓度分布相互印证,我国高浓度O₃主要分布在东部人口密集、经济发达的区域,并且呈现夏季高、冬季低的季节分布趋势.4个重点关注城市（北京、上海、广州、成都）O₃日变化均呈现单峰分布,最高值在每日15：00~16：00.统计分析发现,4个城市除上海市之外,其他3个城市O₃浓度在周末和工作日没有显著差别,表明O₃的"周末效应"减弱.2013年4月~2018年6月,我国地面观测O₃浓度呈现明显上升趋势.2014~2017年,北京、上海和成都市近地面O₃浓度分别以2.36、3.3和3.6 μg·（m³·a）^-1的速度显著上升.4个城市2014~2017年O₃超标天数占比分别为17.2%（北京）、10.7%（上海）、8.8%（广州）和11.2%（成都）,北京市O₃超标天数最多、超标期间O₃浓度最高,O₃污染最为严重.