The Value of Animal Test Information in Environmental Control Decisions

Value of information (VOI)analytic techniques are used to evaluate the benefit of performing animal bioassays to provide information about the cancer potency of specific chemical compounds. These tools allow the identification of the conditions in which the cost of reducing uncertainty about potency, by performing a subchronic or chronic bioassay, is justified by the benefit of having improved information for making control decisions. The decision analytic results are readily scaled to apply to a range of human contact rates (exposures)and a variety of control strategies. The sensitivity of results to uncertainty about animal to human extrapolation and the design of the bioassay is explored. An evaluation of the possible gains in general understanding about the mechanisms of carcinogenicity resulting from chronic bioassays is beyond the scope of this approach.     

Risk-Based Environmental Remediation: Bayesian Monte Carlo Analysis and the Expected Value of Sample Information

A methodology that simulates outcomes from future data collection programs, utilizes Bayesian Monte Carlo analysis to predict the resulting reduction in uncertainty in an environmental fate-and-transport model, and estimates the expected value of this reduction in uncertainty to a risk-based environmental remediation decision is illustrated considering polychlorinated biphenyl (PCB) sediment contamination and uptake by winter flounder in New Bedford Harbor, MA. The expected value of sample information (EVSI), the difference between the expected loss of the optimal decision based on the prior uncertainty analysis and the expected loss of the optimal decision from an updated information state, is calculated for several sampling plan. For the illustrative application we have posed, the EVSI for a sampling plan of two data points is $9.4 million, for five data points is $10.4 million, and for ten data points is $11.5 million. The EVSI for sampling plans involving larger numbers of data points is bounded by the expected value of perfect information, $15.6 million. A sensitivity analysis is conducted to examine the effect of selected model structure and parametric assumptions on the optimal decision and the EVSI. The optimal decision (total area to be dredged) is sensitive to the assumption of linearity between PCB sediment concentration and flounder PCB body burden and to the assumed relationship between area dredged and the harbor-wide average sediment PCB concentration; these assumptions also have a moderate impact on the computed EVSI. The EVSI is most sensitive to the unit cost of remediation and rather insensitive to the penalty cost associated with under-remediation.     

The Value of Information in Decision‐Analytic Modeling for Malaria Vector Control in East Africa

Decision analysis tools and mathematical modeling are increasingly emphasized in malaria control programs worldwide to improve resource allocation and address ongoing challenges with sustainability. However, such tools require substantial scientific evidence, which is costly to acquire. The value of information (VOI) has been proposed as a metric for gauging the value of reduced model uncertainty. We apply this concept to an evidenced‐based Malaria Decision Analysis Support Tool (MDAST) designed for application in East Africa. In developing MDAST, substantial gaps in the scientific evidence base were identified regarding insecticide resistance in malaria vector control and the effectiveness of alternative mosquito control approaches, including larviciding. We identify four entomological parameters in the model (two for insecticide resistance and two for larviciding) that involve high levels of uncertainty and to which outputs in MDAST are sensitive. We estimate and compare a VOI for combinations of these parameters in evaluating three policy alternatives relative to a status quo policy. We find having perfect information on the uncertain parameters could improve program net benefits by up to 5–21%, with the highest VOI associated with jointly eliminating uncertainty about reproductive speed of malaria‐transmitting mosquitoes and initial efficacy of larviciding at reducing the emergence of new adult mosquitoes. Future research on parameter uncertainty in decision analysis of malaria control policy should investigate the VOI with respect to other aspects of malaria transmission (such as antimalarial resistance), the costs of reducing uncertainty in these parameters, and the extent to which imperfect information about these parameters can improve payoffs.     

The Value of Improved National Exposure Information for Perchloroethylene (Perc): A Case Study for Dry Cleaners

Opportunities to improve our information about risk continue to arise and lead decision makers to indirectly address the issue of the value of improved information through resource allocation decisions. Statistical decision analysis techniques provide an analytical framework for valuing information explicitly in the context of regulatory decision making. This paper provides estimates of the value of improved national estimates of perchloroethylene (perc) exposure from U.S. dry cleaners in the context of EPA's recently promulgated National Emissions Standard for Hazardous Air Pollutants (NESHAP) with emphasis on exposure information. Consistent with the NESHAP decision, we relied on EPA's technology and economic assessments. In this first cut analysis, estimates of the exposures of workers, consumers of dry cleaning services, and the general public are probabilistically characterized to reflect uncertainty about exposure and potency. We consider the net benefits of the different control options by assessing the associated changes in the total annual population risks and valuing them in monetary terms, with no constraints placed on maximum individual risks. The results suggest that the expected value of perfect information (EVPI) about potency exceeds the EVPI about exposure. Sensitivity analyses demonstrate how the choices of the valuation parameters and distributions used to characterize uncertainty in the model affect the estimates of the value of information.     

Tiered Chemical Testing: A Value of Information Approach

In December 2000 the EPA initiated the Voluntary Children's Chemical Evaluation Program (VCCEP) by asking manufacturers to voluntarily sponsor toxicological testing in a tiered process for 23 chemicals selected for the pilot phase. The tiered nature of the VCCEP pilot program creates the need for clearly defined criteria for determining when information is sufficient to assess the potential risks to children. This raises questions about how to determine the "adequacy" of the existing information and assess the need to undertake efforts to reduce uncertainty (through further testing). This article applies a value of information analysis approach to determine adequacy by modeling how toxicological and exposure data collected through the VCCEP may be used to inform risk management decisions. The analysis demonstrates the importance of information about the exposure level and control costs in making decisions regarding further toxicological testing. This article accounts for the cost of delaying control action and identifies the optimal testing strategy for a constrained decisionmaker who, absent applicable human data, cannot regulate without bioassay data on a specific chemical. It also quantifies the differences in optimal testing strategy for three decision criteria: maximizing societal net benefits, ensuring maximum exposure control while net benefits are positive (i.e., benefits outweigh costs), and controlling to the maximum extent technologically feasible while the lifetime risk of cancer exceeds a specific level of risk. Finally, this article shows the large differences that exist in net benefits between the three criteria for the range of exposure levels where the optimal actions differ.     

Promoting Transparency of Long-Term Environmental Decisions: The Hanford Decision Mapping System Pilot Project

Nuclear waste cleanup is a challenging and complex problem that requires both scientific analysis and dialogue among a variety of stakeholders. This article describes an effort to develop an online information system that supports this analytic-deliberative dialogue by integrating cleanup information for the Hanford Site, and making it more "transparent." A framework for understanding and evaluating transparency guided system development. Working directly with stakeholders, we identified information needs and developed new ways to organize and present the information so that it would be more transparent to interested parties, with the ultimate aim of fostering greater participation in decision dialogues and processes. The complexity of the information needed for dialogue suggested that several types of communication devices ("information structures") were warranted. Five information structures were developed for the pilot Decision Mapping System (http://nalu.geog.washington.edu/dms). Decision maps hyperlinked decision information to maps of Hanford. Background Information provided context in a narrative format. Decision Paths organized decision process information on a timeline and provided direct hyperlinks to online documentation. The Geographic Library hyperlinked decision documents to maps. Finally, a Discussion Forum allowed users to make comments and view remarks from others. Early lessons from this work suggest that transparency is integral to long-term management, a participatory design process contributed greatly to its perceived success, and better data integration to support decision making is needed. This work has broad implications for risk communicators and risk managers because it speaks to the design of information systems to support "analytic-deliberative" decision processes (i.e., those that rely upon both risk science and public dialogue).     

实施建筑节能标准的宏观经济和环境影响测算模型研究

本文首先对实施建筑节能标准的主要经济和环境影响方面进行系统分析,然后对投入产出局部闭模型进行了改进,并结合数量经济和静态比较的方法,创建了实施建筑节能标准的宏观经济和环境影响测算模型。该模型可以从6个主要方面详细测算实施建筑节能标准对各个产业部门的直接经济影响、直接环境影响、完全经济影响和对GDP的总影响。模型测算结果表明,建筑节能的节能和减排效果显著,同时对GDP有小幅的拉动作用,随着建筑节能标准实施率的增加,它对GDP的拉动强度呈先增后减的趋势。最后根据对测算结果的分析,提出推广实施建筑节能标准的具体方法建议。     

Deciding with Thresholds: Importance Measures and Value of Information

Risk‐informed decision making is often accompanied by the specification of an acceptable level of risk. Such target level is compared against the value of a risk metric, usually computed through a probabilistic safety assessment model, to decide about the acceptability of a given design, the launch of a space mission, etc. Importance measures complement the decision process with information about the risk/safety significance of events. However, importance measures do not tell us whether the occurrence of an event can change the overarching decision. By linking value of information and importance measures for probabilistic risk assessment models, this work obtains a value‐of‐information‐based importance measure that brings together the risk metric, risk importance measures, and the risk threshold in one expression. The new importance measure does not impose additional computational burden because it can be calculated from our knowledge of the risk achievement and risk reduction worth, and complements the insights delivered by these importance measures. Several properties are discussed, including the joint decision worth of basic event groups. The application to the large loss of coolant accident sequence of the Advanced Test Reactor helps us in illustrating the risk analysis insights.     

The Value of Information for Managing Retail Inventory Remotely

An important difference between both manufacturing and wholesaling vs. retail is the information available concerning inventory. Typically, far less information characterizes retail. Here, an extreme environment of information shortfall is examined. The environment is technically termed “unattended points of sale,” but colloquially called vending machines. Once inventory is loaded into a machine, information on demand and inventory level is not observed until the scheduled reloading date. Technological advances and business process changes have drawn attention to the value of information (VOI) in retail inventory in many venues. Moreover, technology is now available that allows unattended points of sale to report inventory information. Capturing the value of this information requires changes in current business practice. We demonstrate the value of capturing information analytically in an environment with restrictive demand assumptions. Experiments in an environment with realistic demand assumptions and parameter values show that the VOI depends greatly on operating characteristics and can range from negligible effects to increasing profitability 30% or more in actual practice.     

考虑信息搜索的环境污染群体性事件最优决策模型

坚决打好污染防治攻坚战是建设全面小康社会三大任务之一,环境污染群体性事件影响社会稳定和生态文明建设。在当今信息渠道多元化的自媒体时代下,群众能够通过信息搜索行为为决策获取信息。本文考虑了群众信息搜索行为,构建周边居民信息搜索的环境污染群体性事件最优决策模型,分析了不同条件下均衡策略选择,以及在各种地方政府补贴水平和暗箱操作程度下,周边居民的收益变化情况和策略选择差异。结果表明：当政府的暗箱操作程度较低时,群众的最优化策略为信息搜索后“污染轻微”则“抗议”,否则群众的最优化策略为直接抗议。当群众对项目污染程度为严重的先验概率较低且政府的暗箱操作程度比较高时,群众将选择不抗议策略。当周边居民的识别能力较差,群众将会选择策略信息搜索后“污染轻微”则“不抗议”,当暗箱操作程度足够大时,群众将会选择策略直接抗议。随着地方政府提供补贴水平的增加,群众的抗议强度减弱。了解群众的最优决策,有利于政府对环境群体性事件进行防范和应对,维护社会稳定。     

The Law of Large Demand for Information

An unresolved problem in Bayesian decision theory is how to value and price information. This paper resolves both problems assuming inexpensive information. Building on Large Deviation Theory, we produce a generically complete asymptotic order on samples of i.i.d. signals in finite–state, finite–action models. Computing the marginal value of an additional signal, we find it is eventually exponentially falling in quantity, and higher for lower quality signals. We provide a precise formula for the information demand, valid at low prices: asymptotically a constant times the log price, and falling in the signal quality for a given price.     

Safety Risk Analysis of an Innovative Environmental Technology

The authors describe a decision and risk analysis performed for the cleanup of a large Department of Energy mixed-waste subsurface disposal area governed by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). In a previous study, the authors worked with the site decision makers, state regulators, and U.S. Environmental Protection Agency regional regulators to develop a CERCLA-based multiobjective decision analysis value model and used the model to perform a screening analysis of 28 remedial alternatives. The analysis results identified an innovative technology, in situ vitrification, with high effectiveness versus cost. Since this technology had not been used on this scale before, the major uncertainties were contaminant migration and pressure buildup. Pressure buildup was a safety concern due to the potential risks to worker safety. With the help of environmental technology experts remedial alternative changes were identified to mitigate the concerns about contaminant migration and pressure buildup. The analysis results showed that the probability of an event with a risk to worker safety had been significantly reduced. Based on these results, site decision makers have refocused their test program to examine in situ vitrification and have continued the use of the CERCLA-based decision analysis methodology to analyze remedial alternatives.     

The U.S. EPA Geographic Information System for Mapping Environmental Releases of Toxic Chemical Release Inventory (TRI) Chemicals

This study characterizes the environmental releases of toxic chemicals of the Toxic Chemical Release Inventory (TRI) in the southeastern United States by using the U.S. Environmental Protection Agency (EPA) Geographic Information System (GIS) to map them. These maps show that the largest quantities of TRI releases in the Southeast are usually near densely populated areas. This GIS mapping approach takes the first steps in defining those areas in the region which may be potential exposure zones and which could be strategic targets for future risk screening efforts in this geographic area.     

无外部市场条件下中间产品转移价格的博弈分析与决策

本文首先用反例证明了文^[1]中在各分厂成本函数和最终产品需求函数已知的条件下,给出的中间产品最优转移价格的两个计算公式并不总是成立的,给出了这两个计算公式成立的充要条件,并分析了公司关于中间产品转移价格决策的动态一致性问题。接着,利用完全信息动态博弈对中间产品转移价格的确定问题做了进一步的分析研究。最后,针对文^[1]中给出的中间产品最优转移价格的两个计算公式不成立的情况,讨论了中间产品转移价格的确定问题。     

The Quality of Stakeholder-Based Decisions

The increased use of stakeholder processes in environmental decision making has raised concerns about the quality of decisions these processes produce. Some claim that stakeholders make inadequate use of scientific information and analysis and are all too ready to sacrifice technical quality for political expediency. This article looks to the case study record to examine the quality of the decisions from stakeholder-based processes. The data for the analysis come from a "case survey," in which researchers coded information from 239 published case studies of stakeholder involvement in environmental decision making. These cases reflect a diversity of planning, management, and implementation activities carried out by environmental and natural resource agencies at many levels of government. Overall, the case-study record suggests that there should be little concern that stakeholder processes are resulting in low-quality decisions. The majority of cases contain evidence of stakeholders improving decisions over the status quo; adding new information, ideas, and analysis; and having adequate access to technical and scientific resources. Indeed, data suggest that it is the more intensive stakeholder processes--precisely those that have aroused recent concern--that are more likely to result in higher-quality decisions.     

Value of Information in Closed Loop Supply Chains

We explore the value of information (VOI) in the context of a firm that faces uncertainty with respect to demand, product return, and product recovery (yield). The operational decision of interest in matching supply with demand is the quantity of new product to order. Our objective is to evaluate the VOI from reducing one or more types of uncertainties, where value is measured by the reduction in total expected holding and shortage costs. We start with a single period model with normally distributed demands and returns, and restrict the analysis to the value of full information (VOFI) on one or more types of uncertainty. We develop estimators that are predictive of the value and sensitivity of (combinations of) different information types. We find that there is no dominance in value amongst the different types of information, and that there is an additional pay‐off from investing in more than one type. We then extend our analysis to the multi‐period case, where returns in a period are correlated with demands in the previous period, and study the value of partial information (VOPI) as well as full information. We demonstrate that our results from the single period model (adapted for VOPI) carry‐over exactly. Furthermore, a comparison with uniformly distributed demand and return show that these results are robust with respect to distributional assumptions.     

基于环境信息和金融市场不对称博弈模型分析

由于金融市场存在信息不对称使得投资决策者缺乏必要的环境信息,从而导致了投资决策信息不完全、金融资金分配不合理等问题。本文在Nikolaou,Chymis和Evangelinos^[5]提出的环境信息、金融市场不对称博弈模型的基础上,引入政府局中人行为策略,构建了政府、企业与金融市场之间的博弈模型。通过设置相关参数发现,该博弈模型能够覆盖Nikolaou,Chymis和Evangelinos^[5]提出的模型,并证明了在政府局中人参与并满足一定条件的情况下,由环境信息缺失引起的信息不对称问题可以通过引入第三方国际环境审计来解决,从而为我国环境污染问题的化解机制提供新的研究角度。     

Uncertainty and the Value of Information with Stochastic Losses from Global Warming

We present an uncertainty analysis conducted using CETA-R, a model in which the costs of climate change are specified as Risks of large losses. In this analysis, we assume that three key parameters may each take on "high" or "low" values, leading to eight possible states of the world. We then explore optimal policies when the state of the world is known, and under uncertainty. Also, we estimate the benefits of resolving uncertainty earlier. We find that the optimal policy under uncertainty is similar to the policy that is optimal when each of the key parameters is at its low value. We also find that the value of immediate uncertainty resolution rises sharply as the alternative to immediate resolution is increasingly delayed resolution.