Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

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Economics of natural resources and the environment

This article proposes contemporary best-practice recommendations for stated preference (SP) studies used to inform decision making, grounded in the accumulated body of peer-reviewed literature. These recommendations consider the use of SP methods to estimate both use and non-use (passive-use) values, and cover the broad SP domain, including contingent valuation and discrete choice experiments. We focus on applications to public goods in the context of the environment and human health but also consider ways in which the proposed recommendations might apply to other common areas of application. The recommendations recognize that SP results may be used and reused (benefit transfers) by governmental agencies and nongovernmental organizations, and that all such applications must be considered. The intended result is a set of guidelines for SP studies that is more comprehensive than that of the original National Oceanic and Atmospheric Administration (NOAA) Blue Ribbon Panel on contingent valuation, is more germane to contemporary applications, and reflects the two decades of research since that time. We also distinguish between practices for which accumulated research is sufficient to support recommendations and those for which greater uncertainty remains. The goal of this article is to raise the quality of SP studies used to support decision making and promote research that will further enhance the practice of these studies worldwide.

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Contemporary Guidance for Stated Preference Studies

In this paper recent developments in the estimation of frontier functions and the measurement of efficiency are surveyed, and the potential applicability of these methods in agricultural economics is discussed. Frontier production, cost and profit functions are discussed, along with the construction of technical, allocative, scale and overall efficiency measures relative to these estimated frontiers. The two primary methods of frontier estimation, econometric and linear programming, are compared. A survey of recent applications of frontier methods in agriculture is also provided. (This abstract was borrowed from another version of this item.)

Recent Developments in Frontier Modelling and Efficiency Measurement

Drought is a complex natural hazard that impacts ecosystems and society in many ways. Many of these impacts are associated with hydrological drought (drought in rivers, lakes, and groundwater). It is, therefore, crucial to understand the development and recovery of hydrological drought. In this review an overview is given of the current state of scientific knowledge of definitions, processes, and quantification of hydrological drought. Special attention is given to the influence of climate and terrestrial properties (geology, land use) on hydrological drought characteristics and the role of storage. Furthermore, the current debate about the use and usefulness of different drought indicators is highlighted and recent advances in drought monitoring and prediction are mentioned. Research on projections of hydrological drought for the future is summarized. This review also briefly touches upon the link of hydrological drought characteristics with impacts and the issues related to drought management. Finally, four challenges for future research on hydrological drought are defined that relate international initiatives such as the Intergovernmental Panel on Climate Change (IPCC) and the ‘Panta Rhei’ decade of the International Association of Hydrological Sciences (IAHS). WIREs Water 2015, 2:359–392. doi: 10.1002/wat2.1085

For further resources related to this article, please visit the WIREs website.

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Hydrological drought explained

Economics of Rainfed and Irrigated Potato Production in a Humid Environment

En el presente estudio se aplica un analisis de eficiencia con una metodologia no parametrica (DEA) sobre un conjunto de datos de panel conformado por 35 explotaciones lecheras ubicadas en la Cuenca de Abasto Sur de Buenos Aires, Argentina. El analisis se baso en modelos con rendimientos constantes a escala y variables a escala, bajo dos enfoques: inputorientado y output-orientado. Se utilizo un unico output, la produccion de leche; y tres inputs: la superficie ganadera, el numero de vacas lecheros y el resto de costes expresados en dinero. Los resultados muestran un promedio de eficiencia tecnica global de 78,2 por ciento, con una mayoria de firmas operando con rendimientos crecientes a escala. Un resultado interesante del analisis es la existencia de firmas tecnicamente eficientes pero operando con un nivel de intensificacion tal que provoca un costo de produccion superior al precio de la leche.

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Un análisis no paramétrico de eficiencia en explotaciones lecheras de Argentina

The single objective—profit maximization—has been the classical and neoclassic model for farmer’s decision making. Nowadays, it is recognized that other and conflictual objectives are important concerns to the process, making the multi-criteria methodologies more suitable to the agricultural reality. This chapter aims to identify and find the objectives and priorities of the Azorean dairy farmer’s decision making. The proposed methodology is based on multi-criteria models, by simulation of the dairy farmers’ behavior through data of the Farm Accountancy Data Network. This allows to define a surrogate utility function for a dairy farm typology, regarding the different grazing systems. Five main objectives were previously considered: profit maximization, risk minimization, labor seasonality minimization, leisure maximization, and also deviations to the goal of total labor minimization. The results show that in any group of Azorean dairy farms, the decision making process seems to be influenced by three conflictual objectives: profit maximization, labor seasonality, and risk minimization. Also, the farms’ objectives depend on the intensity of grazing systems and by other socioeconomic factors. That is, farmers’ behavior is not always explained by profit (exception in the low intensity grazing systems), which is unusual under the traditional paradigm. Some explanations may be appointed for this situation and one is related to the dairy farms income that can be enough to maintain the farm and family income. If the economic objectives are satisfied, then the farmers can have other priorities.

Julio Berbel

Papers

Economics of Rainfed and Irrigated Potato Production in a Humid Environment

Un análisis no paramétrico de eficiencia en explotaciones lecheras de Argentina

The Objectives and Priorities for the Azorean Dairy Farmers’ Decisions

Socioeconomic impact of 2005-2008 drought in Andalusian agriculture.

A decision model for stochastic optimization of seasonal irrigation-water allocation