Séminaires 2017-2016

11 décembre 2017

Adoption of mitigation practices in agriculture: an application of the option-value theory
Camille Tévenart

Résumé :

Uncertainty about new farming practices is considered in the literature as a key barrier to their adoption. Mitigation practices that bear potential extra benefits are barely adopted by farmers, putting in evidence some hidden costs to adoption. Some previous research highlighted some behavior related to uncertainty and risk, leading to partial, sequential adoption, or non-adoption by farmers, regarding their farms’ characteristics and their attitudes toward risk. In this paper, we adapt an “Option value model” to the adoption of mitigation practices by farmers, in a land management framework. This farming portfolio model allows to take into account the level of adoption of new practices, the irreversibility of the conversion of lands into new practices, and the possibility of the permanence of conventional practices on some part of the farm depending on the beliefs of farmers about new practices’ yields, and their own characteristics. The partial adoption associated to option value emerges when farmers exhibit aversion toward risks, that can lead to the disincentives to adopt further in order to wait for more favorable conditions to adopt, and keep the conventional practices at a sufficient level. The role of diverse choice criteria, like the farm size effect and information arrival, is also assessed. Public policies implications are derived from the results.

6 novembre 2017

Impacts of land use and climate change on freshwater biodiversity in France
Basak Bayramoglu et Raja Chakir

Résumé :

The objective of this paper is to analyze the impacts of land use (agriculture, forest, pasture, urban) and climate change on freshwater biodiversity, measured by a fish-based index (FBI) for various French rivers observed between 2001 and 2013. We estimate a spatial econometric land use share model and a statistical spatial panel FBI model. The land use share model describes how land use is affected by economic, pedo-climatic and demographic factors, while the FBI model explains the spatial and temporal distribution of the FBI score by land use and pedo-climatic variables. Our estimation results reveal that rivers in areas with more intensive agriculture and steep pasture are associated to lower freshwater biodiversity compared to forest areas. Our simulations show that climate change will exacerbate negative land use impacts through land-use adaptation, on freshwater biodiversity. We discuss how two command-and-control policies could help improve freshwater biodiversity and cope with the adverse effects of land use and climate change.

3 avril 2017

The impacts of climate change on French agricultural productivity
Simone Pieralli

27 février 2017
Land use analysis and ecosystem services
Lise Daunes

Résumé :

Land use and land use change are among the major human pressures on the environment, especially on ecosystem services. This paper investigates the consequences of land use and land use change on biodiversity conservation and carbon sequestration. It gives insights about the trade-offs between private landowner economic goal and environmental objectives through a theoretical and an econometric models. We implement a theoretical approach where a representative landowner compares the land use rents to choose the optimal land use. Carbon sequestration and biodiversity are introduced through suitable indicators. We highlight trade-offs between economic (profit maximization) and environmental objectives (carbon sequestration and biodiversity conservation) by implementing different public policy scenarios (through taxes and subsidies). We test the previous insights with an econometric application. A land use share model is estimated for major land uses in France. Land use is explained by economic variables (land rents) and on biophysical variables (climate, soil characteristics). Several ecosystem services are taking into account and are function of land use share.

 
30 janvier
Pollution-adjusted productivity changes in French suckler cow farms: The use of a generalized multiplicatively complete Färe-Primont index
Hervé Dakpo

Résumé :

This article extends the multiplicatively complete Färe-Primont productivity index to a generalized version that considers pollution. The proposed total factor productivity (TFP) writes as the ratio of an aggregated good outputs to an aggregated bad outputs and non-polluting inputs in such a way that the materials balance principle is not distorted. A decomposition of the new pollution-adjusted total factor productivity (PTFP) is proposed using the by-production approach. In general, the by-production implies considering a global technology that lies at the intersection of two sub-technologies: one for the production of good outputs and the other for the generation of pollution. Using different assumptions, the PTFP is decomposed into pollution-adjusted technical and efficiency changes. The latter driver is further broken down into technical, scale, mix or residual efficiency changes components. A real advantage of the Färe-Primont index is the verification of the transitivity property which allows multi-temporal and multi-lateral comparisons. It is thereby useful for most panel databases at hand. The generalized Färe-Primont PTFP is illustrated in this article with a sample of French suckler cow farms surveyed over the period 1990 to 2013. The bad outputs considered are the greenhouses gases emissions namely methane (CH₄), carbon dioxide (CO₂) and nitrous oxide (N₂O). The results reveal a decrease in pollution-adjusted TFP by 5.57% over the period, due to technological regress of 2.23%, and to technical efficiency decrease for almost 3.34%. This suggests that farmers did not have the right incentives to implement actions that would reduce such emissions during the period studied.

9 janvier 2017
Ressources renouvelables et aversion à l'inégalité : quelles conséquences pour le futur ?
Stellio Del Campo

Résumé :
This paper addresses intragenerational and intergenerational issues about a renewable natural resource exploitation. In particular, we analyze how different equity views, represented through a change in the intragenerational inequality aversion, influence the possible development paths for future generations. We suppose an agent has access to a renewable resource and works to exploit it, while another agent does not have access to it. A social planner implements a transfer mechanism from the former to the latter. We show that if the worker is originally better-off than the receiver, inequality aversion has a negative effect on the resource stock with a lump-sum transfer, but potentially a positive effect with a proportional tax. Reciprocally, the higher the stock the higher the possibilities for future consumptions. These links strongly suggest to deal jointly with the two equity dimensions in order to design consistent environmental policies.

12 décembre 2016
Les interrelations entre services écosystémiques et le rôle des politiques agroenvironnementales
Barbara Langlois