• Energy Research
• FR close
• English close
• Research Papers in Economics close

International audience This communication presents four contrasted and near-caricatured scenarios of retail location and distribution, and compares them on the bases of both road occupancy rates and greenhouse gas emissions. Two main families of scenarios are defined: retailing land-use scenarios, based on the location of the different retailing activities of a city, and end-consumer delivery organisational scenarios, based on the definition of new services to deliver end-consumers, at home or to reception points. Those scenarios are simulated using an integrated approach combining inter-establishement goods transport flows, shopping trips and end-consumer deliveries. The simulation approach is able to show the relation between several aspects of retailing deployment (store location, catchment area's supply, urban retailing planning policies) and both upstream distribution of goods to retailers and downstream usage of private vehicles for shopping. Although scenarios are extreme and near-caricatured, they are able to identify the limits and forces of the different retailing strategies in urban zones.

Within an overall project to assess the ability of the agricultural sector to contribute to bioenergy production, we set out here to examine the economic and technological viability of a bioenergy facility in an uncertain economic context, using the stochastic viability approach. We consider two viability constraints: the facility demand for lignocellulosic feedstock has to be satisfied each year and the associated supply cost has to be lower than de profitability threshold of the facility. We assess the viability probability of various supplying strategies consisting in contracting a given share of the feedstock demand with perennial dedicated crops at the initial time and then in making up each year with annual dedicated crops or wood. The demand constraints and agricultural prices scenarios over the time horizon are introduced in an agricultural and forest biomass supply model, which in turns determines the supply cost per MWh and computes the viability probabilities of the various contract strategies. A sensibility analysis to agricultural prices at initial time is performed. Results show that when they are around or under the median (of the 1993–2007 prices), the strategy consisting in contracting 100% of the feedstock supply with perennial dedicated crops is the best one.

Dans le paysage des propositions de comptabilité nationale rénovée et de nouveaux indicateurs de bien-être et de soutenabilité, l'approche de la Richesse Inclusive (Inclusive Wealth Framework) et l'Indicateur de Richesse Inclusive qui lui est associé, lancés en juin 2012 pendant le sommet "Rio + 20", sont particulièrement en vue. Construit à la confluence de l'économie du bien-être, de l'économie du développement et de l'économie de la soutenabilité, l'indicateur est supposé informer, de manière exhaustive (inclusive), sur la richesse des nations et leur soutenabilité. Mais le cadre d'analyse de la Richesse Inclusive présente de nombreux problèmes liés à ses hypothèses et à des insuffisances dans la disponibilité des données. Nous montrons que ces problèmes empêchent l'IWI d'atteindre les objectifs de ses auteurs. Plus fondamentalement, l'IWI ne satisfait pas les conditions d'un bon indicateur de soutenabilité. Nous mettons en question les prétentions de l'économie (néoclassique) à pouvoir traiter des enjeux complexes, incertains et variés, notamment à l'aide d'hypothèses de non-optimalité. Nous évoquons ensuite des pistes de recherche alternatives, dont les fondements nous semblent plus à même de développer une approche forte de la soutenabilité dans une perspective moins économiciste. Le choix de nouveaux indicateurs de prospérité ne doit pas reposer sur des critères d'élégance formelle ou de prétendue cohérence théorique. Among recent high-profile propositions to revise national accounts and to provide new indicators of sustainability and well-being, the Inclusive Wealth Framework and the related Inclusive Wealth Index (thereafter IWI), first released during the "Rio+20" Conference, undoubtedly stand out as the most promising endeavour. Built up at the confluence of welfare, development and sustainability economics, the indicator is supposed to bring information about the wealth of nations and their sustainability, in a comprehensive way. The inclusive wealth framework is nevertheless fraught with limitations, due to questionable theoretical assumptions and gaps in data availability. We propose a critical appraisal of the index and its underlying framework. Our conclusion is that these limitations undermine its capacity to reach the goals it was given, and to fulfill the requirements of a satisfactory sustainability indicator. Special emphasis is put on the misleading pretension of (neoclassical) economics to handle highly complex, uncertain and manifold issues, even on theoretical bases renovated by dropping some optimality assumptions. We briefly sketch alternative research avenues, that appear more conducive to the endorsement of strong sustainability, and less prone to economism. Alleged theoretical consistency and elegance should not beguile us when choosing indicators for sustainable and prosperous societies.

The aim of this article is to lay out a series of issues of current concern to researchers in the social sciences, regarding the impact of climate change on the vine and wine sector. The challenge lies in evaluating the cost of transition from one system to another through an integration of the direct and indirect effects of climate change. This adaptation, whether reactive or anticipatory, combines technical and organisational innovations with localisation strategies and institutional changes. Such actions could either try to maintain the existing situation as much as possible or could try to bifurcate towards deep changes, entailing very different costs. Given the multitude of uncertainties at play, not to mention the necessity for continuous adaptation to an ever-changing climate, these costs are hard to quantify. This article will illustrate two sets of measures for wine cultivation adaptation: 'no regrets' measures, which offer immediate benefits, and 'reversible and flexible' measures, which limit the inertia of wine-cultivating systems. In spite of the challenges, what stands out is the evident re-enforcement resulting from the collaboration between researchers and political and economic actors. In the field of wine cultivation, these collaborations can follow two paths: the study of the diversity of existing wine-growing systems and genetic resources or the possibility of more radical technological and social experimentation.

We propose to test the portfolio selection theory on the historical data of tree species’ productivities obtained from the French National Forest Inventory (IFN). We determine the optimal timber productivity-vulnerability arrangements out of the combinations of tree species and map the optimal compositions per administrative department in France. We also estimate the survivals of optimal portfolios using the species’ probabilities of presence. Our results show that greater weights in the optimal portfolios correspond to higher probabilities of presence.

Nous étudions l'exploitation optimale de deux ressources non-renouvelables, quand les coûts d'extraction dépendent de la quantité cumulée déjà extraite. Nous commençons par définir un coût d'usage complet des ressources naturelles, incluant les dommages environnementaux. Nous utilisons ensuite ce cadre d'analyse pour caractériser l'exploitation optimale du pétrole et du charbon. Le coût d'extraction du pétrole est initialement plus bas que celui du charbon, mais il augmente plus rapidement. Le charbon est responsable d'émissions plus importantes. Dans un scénario business as usual le sentier optimal consiste d'abord à n'utiliser que le pétrole puis, dans un second temps, à utiliser simultanément les deux ressources en faisant une place importante au charbon. Quand le prix du carbone est pris en compte, le sentier optimal repose moins sur le charbon et il peut même être optimal de revenir au seul pétrole. We study the optimal extraction of two non-renewable resources when extraction costs depend on cumulative previous extraction. We first define a complete user cost of natural resources, including environmental damages, which allows us to greatly simplify the resolution. This framework is applied to a study of oil and coal optimal extraction. The extraction cost of oil is initially lower than the one of coal but increases more rapidly. Coal leads to higher emissions. In a business as usual scenario the optimal path is to use first only oil, before using the two resources and relying a lot on cheaper coal, until the backstop becomes profitable. When the carbon price is taken into account, the optimal path relies much less on the more polluting coal, and it may be optimal to revert to an oil only trajectory.

Until today, herbicide-tolerant (HT) transgenic crops have been the most widely used type of transgenic crops. In 2008, worldwide, 63% of all agricultural land devoted to transgenic crops involved HT transgenic ones, and the percentage was higher (85%) when the herbicide-tolerant trait was stacked with another. In addition, other HT crops are foreseen within the next five years if we are to believe the "pipeline" of the companies involved along with field trials. However, herbicide-tolerant crops have been criticized, particularly in Europe, because of the type of trait introduced: herbicide tolerance. Indeed, this trait leads the crops to depend on a herbicide (generally glyphosate) instead of freeing them from some pesticides through a better use of their biological capacities and a valorisation of life processes as biotechnology was expected to do. Therefore, how can we explain the widespread use of HT transgenic crops and what are their fallouts? At first the paper presents the extent of surface areas dedicated to these crops and the factors that have led to the development of these herbicide-tolerant crops. Then, the case of glyphosate-tolerant soybeans in the USA is studied in more detail. Its agro-environmental impacts, particularly with regard to trends in the use of herbicides, are analyzed. Thirdly, we address the factors of adoption, economic performance, benefits, and drawbacks of this soybean as well as its prospects. Finally, the conclusion questions the contribution of HT soybean to more sustainable agriculture. IAAE 2009 International Conference