A METHOD FOR INCLUDING IN PMP MODELS ACTIVITIES NON-EXISTENT IN THE BASELINE SITUATION

When working with positive mathematical programming (PMP) models it is generally admitted that it is not possible to consider in the modeled unit activities that are not present in the baseline situation of the unit. This constitutes a considerable drawback for traditional PMP techniques which cannot be applied in specific cases, in particular to the study of the impact of new agri-environmental programs that subsidize crops grown with technologies different to those applied in the baseline situation. This paper presents a method for dealing with these cases, which can be easily implemented as an extension of the traditional calibration techniques of PMP. The method is applied to a specific problem, using modified calibration expressions derived from the necessary Khun-Tucker conditions, assuming increasing marginal costs. The analysis of the results and their comparison with those obtained using a linear programming model permits a first evaluation of this methodological proposal.Positive mathematical programming extensions, Agri-environmental measures, Environmental Economics and Policy,

IMPACT OF THE CAP REFORM ON THE SPANISH AGRICULTURAL SECTOR

This paper analyses the impact of the 2003 CAP reform on Spanish agricultural sector in the context of the recent CAP Health Check and high food prices, using PROMAPA, a positive mathematical programming model for representative farms. The analysis compares the model results for base year 2002 to the findings for a scenario with the CAP reform measures in place, taking into account recent modifications. The effect of adopting a full decoupling scheme instead of the present partial decoupling is also studied. Brief descriptions are given of the PROMAPA model, the representative farm considered and the assumptions about both price variations and the policy measures simulated. The findings showed that the farming area for cereals grew substantially after abolition of the compulsory set-aside and that the impact of transition to full decoupling was scant, except in the sheep and rearing cattle sub-sectors, where it considerably steepened the already sizeable decline in livestock numbers induced by the partial decoupling scheme.CAP reform, CAP Health Check, Decoupling, Spanish agricultural sector., Agricultural and Food Policy, Q10, Q12, Q18,

Single payment scheme and dual values of land in PMP models

Land dual values are one of the important aspects of the results of mathematical programming models used to evaluate the impact of agricultural policy measures at regional and farm level. When the decoupling of direct payments and the payment entitlements per hectare are included in PMP models in the context of the Single Payment Scheme (SPS), the analysis of the land dual values is more complex than in models which do not take these aspects into account. In this paper, we present a theoretical analysis of the land dual values when the SPS is included in PMP farm models. This theoretical analysis is carried out for the base year (linear model) and for a simulated year (quadratic model).The results of this analysis are illustrated by comparing numerically the land opportunity costs obtained in the case of partial decoupling and in the case of full decoupling of direct payments

A METHOD FOR INCLUDING IN PMP MODELS ACTIVITIES NON-EXISTENT IN THE BASELINE SITUATION

When working with positive mathematical programming (PMP) models it is generally admitted that it is not possible to consider in the modeled unit activities that are not present in the baseline situation of the unit. This constitutes a considerable drawback for traditional PMP techniques which cannot be applied in specific cases, in particular to the study of the impact of new agri-environmental programs that subsidize crops grown with technologies different to those applied in the baseline situation. This paper presents a method for dealing with these cases, which can be easily implemented as an extension of the traditional calibration techniques of PMP. The method is applied to a specific problem, using modified calibration expressions derived from the necessary Khun-Tucker conditions, assuming increasing marginal costs. The analysis of the results and their comparison with those obtained using a linear programming model permits a first evaluation of this methodological proposal

Evaluating the impacts of policy reforms under changing market conditions on olive farming systems in Southern Spain

[EN] This contribution explores the impacts of alternative policy reform and market scenarios on different olive farming systems (conventional, integrated and organic) in the Spanish region of Andalusia, by far the most important olive-growing region in Spain and in the world. It simulates the possible consequences of policy schemes such as decoupling, modulation and agri-environmental measures, using a representative farm Positive Mathematical Programming (PMP) model calibrated with the neutral procedure. Selection of this calibration procedure is based on its better predictive power compared to two other procedures also tested: the average cost procedure and calibration with exogenous elasticities. The impact analysis focuses primarily on the distribution of different farming systems over the production area and on farms’ gross margins. The analysis compares the results of a base year 2002, in which all subsidies are coupled, with those of scenarios entailing decoupled non agri-environmental support and complementary subsidies for integrated olive farming. Input costs and positive and negative price variations with respect to the base year are considered. Results show inter alia that the recent agricultural policy changes favour the growth of integrated olive production. They also show that while decoupling has a small impact on land distribution in an increased price context, it might trigger an abandonment of part of the cultivated area in a decreased price context. This study opens up a new research avenue for the olive sector as it is the first time that farm modelling is used to investigate the impacts of olive agricultural and environmental policies on different market price and input cost settings[FR] Dans cet article, nous allons explorer les effets de différents scénarios de réformes politiques et de marché sur les divers systèmes de production oléicole (conventionnel, intégré et biologique) en Andalousie, la région oléicole la plus importante en Espagne et dans le monde. Une simulation est proposée des possibles conséquences des dispositifs politiques tels que le découplage, la modulation et les mesures agro-environnementales, au moyen d’un modèle de Programmation mathématique positive PMP) d’exploitation type, calibré par la procédure neutre. Le choix de cette procédure de calibrage est basé sur sa meilleure capacité prédictive par rapport à celle des deux autres procédures également testées: le calibrage avec les coûts moyens et avec les élasticités exogènes. L’analyse d’impact est principale ment centrée sur la distribution superficielle des différents systèmes de production ainsi que sur les marges brutes des exploitations. L’analyse compare les résultats d’une année de base, 2002, pendant laquelle toutes les subventions sont couplées, avec ceux des scénarios comportant des soutiens non-agri-environnementaux découplés et des subventions complémentaires pour l’oléiculture intégrée. Les coûts des intrants et les variations positives et négatives de prix par rapport à l’année de base sont pris en considération. Les résultats montrent inter alia que les changements récents des politiques agricoles favorisent l’expansion de l’oléiculture intégrée. Ils montrent également que, bien que le découplage ait une faible incidence sur la distribution des terres dans un contexte de prix élevés, il pourrait provoquer l’abandon d’une partie de la surface cultivée dans un contexte de prix à la baisse. Cette étude ouvre une nouvelle voie de recherche pour le secteur oléicole, puisque c’est la première fois que ce type de modélisation est utilisé pour étudier les impacts des politiques agricoles et environnementales de l’olivier dans différents contextes de prix de marché et de coûts des intrants.This research is co-funded by the European Commission through FP7 project ‘Sustainable agri-food systems and rural development in the Mediterranean Partner Countries’(SUSTAINMED), and the Spanish Government through National R&D project ‘A model for evaluating the impacts of recent CAP measures on the Spanish agricultural secto

Évaluation contingente de l'usage récréatif d'une réserve naturelle humide

Contingent valuation of the recreational use of a wetland. This paper presents a procedure used to estimate the recreational use value of "Tablas de Daimiel" National Park by applying the Contingent Valuation Method (CVM) with single dichotomous choice, using the truncated mean as welfare measure. This valuation is based on 433 interviews of visitors made during the spring and summer 1996. The sample allocation among the bids offered in the surveys is based on the Duffield and Patterson's method which allows to get the minimal variance of the truncated mean estimator. The recreational values of the Park are not significantly different for the two periods in which the surveys have been carried out. Finally, the tests to study the "interviewers effect" and to analyse the relations between the willingness to pay (WTP) and various interviewees' features don't invalidate the procedure adopted to determine the recreational use value of this National Park.Cet article présente une procédure permettant d'obtenir la valeur récréative du Parc national des Tablas de Daimiel, par la méthode d'évaluation contingente (MEC) avec choix dichotomique simple, et en utilisant la moyenne tronquée comme mesure de bien-être. Cette évaluation a été faite à partir de 433 enquêtes directes auprès des visiteurs du Parc, durant le printemps et l'été 1996. La répartition de l'échantillon entre les valeurs proposées dans les enquêtes se base sur la méthode de Duffield et Patterson qui permet d'obtenir la variance minimale de l'estimateur de la moyenne tronquée. Les valeurs récréatives du Parc national ne sont pas significativement différentes pour les deux périodes au cours desquelles les enquêtes ont été réalisées. Finalement, les tests effectués sur l'«effet des enquêteurs » et à partir de l'analyse des relations entre le consentement à payer (CAP) et certaines caractéristiques des enquêtés n'invalident pas la méthode.Júdez Lucinio, De Andrés Rosario, Pérez Hulgade Carlos, Urzainqui Elvira, Ibánez Miguel. Évaluation contingente de l'usage récréatif d'une réserve naturelle humide. In: Cahiers d'Economie et sociologie rurales, N°48, 3e trimestre 1998. pp. 37-60

Évaluation contingente de l’usage récréatif d’une réserve naturelle humide

This paper presents a procedure used to estimate the recreational use value of “Tablas de Daimiel” National Park by applying the Contingent Valuation Method (CVM) with single dichotomous choice, using the truncated mean as welfare measure. This valuation is based on 433 interviews of visitors made during the spring and summer 1996. The sample allocation among the bids offered in the surveys is based on the Duffield and Patterson’s method which allows to get the minimal variance of the truncated mean estimator. The recreational values of the Park are not significantly different for the two periods in which the surveys have been carried out. Finally, the tests to study the “interviewers effect” and to analyse the relations between the willingness to pay (WTP) and various interviewees’ features don’t invalidate the procedure adopted to determine the recreational use value of this National Park

Cambios en la distribución de cultivos y producciones ganaderas en España inducidos por la nueva PAC

This paper analyses the impact on the Spanish agricultural sector of the CAP decoupling measures of direct payments for different crop areas and livestock.<br /><br /> The study is based in the 2002 data from the Spanish Farm Accountancy Data Network (FADN) and the simulated results are obtained with the mathematical programming model PROMAPA. The predicted changes in prices between the years 2002 and 2013 were those provided by the European Simulation Model (ESIM).<br /><br /> The results obtained permit the comparison of the variation in the crop distribution and of the different types of livestock between the base year 2002 and the simulated year 2013 in the event of the implementation of a partial decoupling policy —as adopted in Spain in 2006— or a full decoupling policy which is under consideration at the moment.<br /><br /> This paper also compares the variations which appear in the two types of decoupling with those that would be obtained in the even of a continuation of the Agenda 2000 measures.<br><br>En este trabajo se analiza el impacto sobre el sector agrario español de las medidas de la Política Agraria Común de desacoplamiento de ayudas directas a las superficies sembradas de distintos cultivos y a las cabezas de ganado.<br /><br /> El análisis se hace en base a los datos de 2002 de la Red Contable Nacional Agraria y a los resultados simulados para 2013 con el modelo de programación matemática PROMAPA, utilizando la predicción de variacion de precios entre 2002 y 2013 del modelo europeo de simulación ESIM.<br /><br /> Los resultados obtenidos permiten comparar los cambios en la distribución de cultivos y de distintas categorías de ganado entre el año base 2002 y el año simulado, 2013, según se siga una política de desacoplamiento parcial, como la implantada en España en 2006, o una política de desacoplamiento total sobre la que se está reflexionando actualmente.<br /><br /> En este trabajo se comparan, por otra parte, los cambios que se observan con los dos tipos de desacoplamiento con los que se obtendrían en el caso de proseguir las medidas vigentes en 2002 en el contexto de la denomina Agenda 2000

IMPACT OF THE CAP REFORM ON THE SPANISH AGRICULTURAL SECTOR

This paper analyses the impact of the 2003 CAP reform on Spanish agricultural sector in the context of the recent CAP Health Check and high food prices, using PROMAPA, a positive mathematical programming model for representative farms. The analysis compares the model results for base year 2002 to the findings for a scenario with the CAP reform measures in place, taking into account recent modifications. The effect of adopting a full decoupling scheme instead of the present partial decoupling is also studied. Brief descriptions are given of the PROMAPA model, the representative farm considered and the assumptions about both price variations and the policy measures simulated. The findings showed that the farming area for cereals grew substantially after abolition of the compulsory set-aside and that the impact of transition to full decoupling was scant, except in the sheep and rearing cattle sub-sectors, where it considerably steepened the already sizeable decline in livestock numbers induced by the partial decoupling scheme

Évaluation contingente de l’usage récréatif d’une réserve naturelle humide

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