Assessing Investment in Precision Farming for Reducing Pesticide Use in French Viticulture

The paper develops a mathematical programming model for assessing the impact of Environmental Policy instruments on French winegrowing farm’s adoption of pesticides-saving technologies. We model choices with regards to investment in precision farming and plant protection practices, in a multi-periodic framework with sequential decision, integrating uncertainty on fungal disease pressure and imperfect information on equipment performance. We focus on recursive models maximizing a Utility function. These models are applied on a representative sample of 534 winegrowers from the French Farm Accountancy Data Network (FADN). As expected, both ecotaxes and green subsidies make precision farming equipment more profitable, but the investment rate remains however low and concentrated on basic systems. One explanation is grower’s financial constraint in a context of market crisis and farm indebtedness. Shortcomings and further development of the models are discussed.Discrete Stochastic Programming, Precision Farming, Viticulture, Pesticides, Environmental Policy, Crop Production/Industries, Farm Management,

Public evaluation of large projects : variational inequialities, bilevel programming and complementarity. A survey

Large projects evaluation rises well known difficulties because -by definition- they modify the current price system; their public evaluation presents additional difficulties because they modify too existing shadow prices without the project. This paper analyzes -first- the basic methodologies applied until late 80s., based on the integration of projects in optimization models or, alternatively, based on iterative procedures with information exchange between two organizational levels. New methodologies applied afterwards are based on variational inequalities, bilevel programming and linear or nonlinear complementarity. Their foundations and different applications related with project evaluation are explored. As a matter of fact, these new tools are closely related among them and can treat more complex cases involving -for example- the reaction of agents to policies or the existence of multiple agents in an environment characterized by common functions representing demands or constraints on polluting emissions

Limiting the Nitrogen Losses by N-tax and Bioenergy Support: A Quantitative Analysis of Environmental Policy Mix Impacts in the North of France

This paper is devoted to assessment of policy mix impacts regarding nitrogen pollutants. The analysed policy combines a tax on the nitrogen input and incentives promoting perennial crops assumed to be low input ones. We show that perennial crop subsidy increases significantly the tax efficiency, compatible with the balanced budget of the Regulatory Agency in charge of the environment. Based on a MILP agricultural supply model, quantitative analysis provides assessment of impacts regarding land use, farmers income, and N losses at the North France level.Bio-economic model, mathematical linear programming, environmental policy mix, N-fertilizer tax, bio-energy support, Environmental Economics and Policy,

Is organic farming inefficient, or are indicators of economic performance of agriculture incomplete?

Organic farming is expected to alleviate the environmental burden of agriculture, since it rules out the use of chemicals such as synthetic fertilizers, pesticides, herbicides. However, organic farming technology may turn out to be less efficient when evaluated by conventional productivity measures that are less informative regarding environmental efficiency. We derive a framework for a combination of more comprehensive indicators reflecting whether organic farming increases sustainability in agriculture and how much of the total agricultural value added is produced at the expense of environmental deterioration. We show that it is important to separate flow and stock effects of pollution so that aggregate measurement is consistent with conventional national accounting. Shadow pricing of undesirable output and policy implications are discussed. For adoption of a technology and allocative efficiency in the agricultural sector, economic policy instruments should be redesigned and proper incentives through prices should be used

OPTIMAL LAND CONVERSION AT THE RURAL-URBAN FRINGE WITH POSITIVE AND NEGATIVE AGRICULTURAL EXTERNALITIES

Bid-rent curves are incorporated in a stochastic dynamic programming model of land development around a city when farmland generates both positive and negative externalities. The model delineates how the quantities of land in various uses over time should depend on the relative social weights assigned to the competing agricultural externalities.Land Economics/Use,

A homotopy approach to the computation of economic equilibria on the unit simplex

Equilibrium Theory

Scrap Value Functions in Dynamic Decision Problems

We introduce an accurate, easily implementable, and fast algorithm to compute optimal decisions in discrete-time long-horizon welfaremaximizing problems. The algorithm is useful when interest is only in the decisions up to period T, where T is small. It relies on a flexible parametrization of the relationship between state variables and optimal total time-discounted welfare through scrap value functions. We demonstrate that this relationship depends on the boundedness, half-boundedness, or unboundedness of the utility function, and on whether a state variable increases or decreases welfare. We propose functional forms for this relationship for large classes of utility functions and explain how to identify the parameters.Scrap value function;Dynamic optimization;Computation;Short horizon.