Can we really use prices to control pesticide use? Results from a nonparametric model

International audienceIn this paper, we assess to what extent pesticide price can be used to bring about more sustainable agricultural practices in field crop farms. We use an innovative three-step nonparametric frontier approach to simulate price increases that would persuade “rational” farmers to adopt practices that use the smallest possible amount of pesticides while still enabling them to continue to produce the same output, given the current production technology. The procedure is based on a data envelopment analysis (DEA) estimation of the production technology. The result suggests that very large price changes are necessary to bring about fairly small change of the quantity of pesticide used, thus challenging the efficacy of price as a policy tool in the short run. Consequently, managing pesticide is likely to require a multi-channel procedure, as prices appear not to be a fully effective instrument. Since the short-run demand structure for pesticides seems to be inelastic, a clear communication of the long-run objective is desirable if not essential for any policy to be implemented

A Note on Conditional Factor Demands and Cost Function

International audienc

From partial derivatives of DEA frontiers to marginal products, marginal rates of substitution, and returns to scale

International audienceThe characterization of a technology, from an economic point of view, often uses the first derivatives of either the transformation or the production function. In a parametric setting, these quantities are readily available as they can be easily deduced from the first derivatives of the specified function. In the standard framework of data envelopment analysis (DEA) models these quantities are not so easily obtained. The difficulty resides in the fact that marginal changes of inputs and outputs might affect the position of the frontier itself while the calculation of first derivatives for economic purposes assumes that the frontier is held constant. We develop here a procedure to recover first derivatives of transformation functions in DEA models and we show how we can evacuate the problem of the (marginal) shift of the frontier. We show how the knowledge of the first derivatives of the frontier estimated by DEA can be used to deduce and compute marginal products, marginal rates of substitution, and returns to scale for each decision making unit (DMU) in the sample

Conditional Factor Demands and Positive Output Effects: A Necessary and Sufficient Condition

International audienceThe duality between cost and production functions has been thoroughly studied and is well-known. A given set ofassumptions on the technology implies a set of restrictions on the Jacobian of the cost function and on a subset of itsHessian matrix. The vector of second derivatives of the cost function with respect to the input prices and the outputhas not been fully characterized, however. In this note, we present a necessary and sufficient condition to ensure thatthe components of this vector are all strictly positive. That is, we specify the condition for all conditional demandfunctions to be simultaneously increasing in output. This condition is interpreted as a strengthening of the quasiconcavity of the production function

Relations bilatérales entre aéroports secondaires et compagnies à bas coût : Quelles justifications concurrentielles sur la base des gains d’efficacité ?

International audienc

The politician and the vote factory: Candidates’ resource management skills and electoral returns

International audienceThis paper disentangles resource management skills of candidates from the electoral circumstances that help them getting (re-)elected. It is first made use of the DEA method to measure candidates’ resource management abilities. Second, determinants of these scores are estimated. The paper uses a database detailing the different sources of campaign funding for French members of Parliament to analyze their relative performance. Results show a large variance in campaign resource management ability, particularly between political parties, and incumbents and newcomers. They also reveal an important role of constituencies’ characteristics and of politicians' experience in explaining differences between politicians' efforts. Thus, public policies could promote virtuous regulations to reduce disparities among candidates with different financial backgrounds and access to resources, to foster a fairer democracy

A mean-maverick game cross-efficiency approach to portfolio selection: An application to Paris stock exchange

International audienc

The impact of single farm payments on technical inefficiency of French crop farms

International audienceAbstractThis paper analyses the effect of single farm payments (SFPs) introduced by the Luxembourg agreements (2003) of the Common Agricultural Policy, on the performance of crop farms in Eure-et-Loir, France, over the period 2005–2008. Technical inefficiency scores of these crop farms are first estimated. Then, the estimated technical inefficiency scores are regressed on SFPs received by farmers following a standard two-step procedure. The analysis shows a negative effect of SFPs on the technical inefficiency of Eure-et-Loir farms. This implies that subsidies granted to farms without production restrictions seem to reduce technical inefficiency