Scaling of the risk landscape drives optimal life history strategies and the evolution of grazing

Consumers face numerous risks that can be minimized by incorporating different life-history strategies. How much and when a consumer adds to its energetic reserves or invests in reproduction are key behavioral and physiological adaptations that structure much of how organisms interact. Here we develop a theoretical framework that explicitly accounts for stochastic fluctuations of an individual consumer's energetic reserves while foraging and reproducing on a landscape with resources that range from uniformly distributed to highly clustered. First, we show that optimal life-history strategies vary in response to changes in the mean productivity of the resource landscape, where depleted environments promote reproduction at lower energetic states, greater investment in each reproduction event, and smaller litter sizes. We then show that if resource variance scales with body size due to landscape clustering, consumers that forage for clustered foods are susceptible to strong Allee effects, increasing extinction risk. Finally, we show that the proposed relationship between consumer body size, resource clustering, and Allee effect-induced population instability offers key ecological insights into the evolution of large-bodied grazing herbivores from small-bodied browsing ancestors.Comment: 9 pages, 5 figures, 3 Supplementary Appendices, 2 Supplementary Figure

Spatial Endogenous Fire Risk and Efficient Fuel Management and Timber Harvest

This paper integrates a spatial fire behavior model and a stochastic dynamic optimization model to determine the optimal spatial pattern of fuel management and timber harvest. Each years fire season causes the loss of forest values and lives in the western US. This paper uses a multi-plot analysis and incorporates uncertainty about fire ignition locations and weather conditions to inform policy by examining the role of spatial endogenous risk - where management actions on one stand affect fire risk in that and adjacent stands. The results support two current strategies, but question two other strategies, for managing forests with fire risk.Resource /Energy Economics and Policy,

Dealing with Major Technological Risks

This article is concerned with the management of major hazards stemming from technology and entailing potentially dreadful consequences. It proposes a brief survey of the0501n difficulties and policy issues arising both in public and private decision making when dealing with major technological risks. Three themes are considered: risk assessment, risk sharing and risk control. Issues related to evaluation methods, to risk perception and to the acceptable level of risk are first examined. The article then goes on to explore the problem of optimal risk sharing between the different stakeholders. The firm's liability and extended liability to the firm's partners are considered. Insurance issues are also discussed. Lastly, the survey addresses the control of risks both from a prevention and from a damage mitigation point of view. The various instruments available to the State to reduce risks are reviewed and several issues are also raised with respect to the measures firms can take to reduce risks. Investment in safety, human error, organisational design and information disclosure are addressed in this section. The topics of siting and urban planning are analysed as mitigation strategies, and the important aspect of emergency planning ends the survey. Cet article d'intérêt général porte sur la gestion des risques d'origine technologique aux conséquences potentiellement catastrophiques. Il s'agit d'un document de synthèse destiné à cerner les problèmes fondamentaux en matière de gestion publique et privée des risques technologiques majeurs. Trois thèmes y sont traités: l'évaluation, la distribution et le contrôle des risques. Les questions se rapportant aux méthodes d'évaluation, à la perception des risques et aux difficultés liées à l'établissement d'un seuil de tolérance sont d'abord passées en revue. La seconde partie du document met en lumière les difficultés que présente le partage optimal du risque entre les différents agents. La responsabilité civile de la firme et de ses partenaires est alors examinée. Les problèmes liés à l'assurance contre ce type de risque sont aussi brièvement décrits. Cet article traite enfin du contrôle des risques en couvrant à la fois les approches préventives et les stratégies d'atténuation des dommages. On y aborde premièrement les instruments de contrôle dont dispose l'État pour réduire les risques. Du côté des firmes, les sujets tels que l'investissement en sécurité, l'erreur humaine, le design organisationnel et la divulgation de l'information sont passés en revue. L'aménagement du territoire et la gestion des urgences sont ensuite abordés de façon succincte dans la dernière partie de l'article.Safety, major risks, risk assessment, risk sharing, risk control, prevention, mitigation, Sécurité, risques majeurs, évaluation des risques, distribution des risques, contrôle des risques, prévention, atténuation

The Economics of Climate Policy

Economics has played an increasingly important role in shaping policy, in the United States and elsewhere. This paper reviews some of the dimensions of the economic approach to analyzing, understanding, and developing solutions to the problem of climate change. We then turn to the issue of designing regulatory instruments to control the problem. The paper concludes with a discussion of the political economy of greenhouse gas control in an international context.climate change, climate policy design, integrated assessment, environmental policy coordination

An Assessment of PIER Electric Grid Research 2003-2014 White Paper

This white paper describes the circumstances in California around the turn of the 21st century that led the California Energy Commission (CEC) to direct additional Public Interest Energy Research funds to address critical electric grid issues, especially those arising from integrating high penetrations of variable renewable generation with the electric grid. It contains an assessment of the beneficial science and technology advances of the resultant portfolio of electric grid research projects administered under the direction of the CEC by a competitively selected contractor, the University of California’s California Institute for Energy and the Environment, from 2003-2014

Whose incentives? The evolution of inheritance practices, intergenerational conflict, and women’s control over land in rural Kenya

Land related investment decisions are shaped by both the formal and informal institutions governing land tenure and acquisition. In the case of agricultural Kikuyu households in Kenya, we show that the inheritance practice of uncertain allocation in conjunction with the principle of equal division among heirs reduces long-term investments in land among potential heirs. This apparent inefficiency is explained by intergenerational power dynamics within the household, as the inheritance practice allows parents to shift the investment incentives facing heirs in their favor. This analytical framework is also used to illustrate that despite legislation formalizing women’s rights to property, control over land continues to follow the informal traditional patrilineal system in important ways.Inheritance, agriculture, Kenya

Management of irrigation water storages: carryover rights and capacity sharing

The intertemporal management of irrigation water involves a consumption-storage decision, where the benefits of using water today are evaluated against the uncertain benefits of storing water for future use. Traditionally in Australia, state governments have centrally managed the major water storages: making decisions on water allocations given prevailing storage levels. However, in practice there are a number of factors which may prevent a centralised approach from achieving an optimal allocation of water. This paper considers in detail two decentralised approaches to storage management: carryover rights and capacity sharing. This paper also presents a quantitative analysis of storage management, involving the application of a stochastic dynamic programming model.