Maria Leonor da Silva Carvalho

Estimation of cost allocation coefficients at the farm level using an entropy approach

This paper aims to estimate the farm cost allocation coefficients from whole-farm input costs. An entropy approach was developed under a Tobit formulation and was applied to a sample of farms from the 2004 Farm Accountancy Data Network data base for Alentejo region, Southern Portugal. A Generalized Maximum Entropy model and Cross Generalized Entropy model were developed to the sample conditions and were tested. Model results were assessed in terms of their precision and estimation power and were compared with the observed data. The entropy approach showed to be a flexible and valid tool to estimate incomplete information, namely regarding farm costs.

As Atitudes dos Agricultores Face à Política Agrícola Comum e ao Projecto de Regadio de Alqueva

The main purpose of this paper is to know farmer’s attitudes face to the agricultural production, the political support and the irrigation project of Alqueva in the context of the 2003 Common Agricultural Policy (CAP) reform and the Health-Check, in a micro-region located near the Mediterranean Sea, in the Southern region of Portugal. At the same time, this paper also aims to understand the behavioural intentions of farmers face to the technological innovation and the future of the irrigation project in this political context. Results show that the majority of farmers are a relatively homogeneous cluster about their attitudes and behavioural intentions. These farmers still maintain a productivist mindset, a strong wish to maintain an agricultural focus and they strongly reject the notions of policy liberalisation. Although they have a great potential of innovation and being aware of the importance of their contribution in the protection of the rural environment, they recognize that the future CAP, the water supply irrigation price and the conditions of access to agricultural credit, could compromise their innovation capacity in the future. The conclusions suggest that it is necessary to understand the particularities of a regional agriculture in different countries in the European Union so the policies can take place successfully. In the Portuguese case, more comprehensive studies are necessary in order to find more consistent results.

Impactes do Preço da Água na Agricultura no Perímetro Irrigado do Vale de Caxito

Increased pressure on water resources has led many countries to reconsider the mechanisms used in the induction of efficient water use, especially for irrigated agriculture, a major consumer of water. Establishing the correct price of water is one of the mechanisms for more efficient allocation of water. This paper aims to analyze the economic, social and essenenvironmental impacts of water price policies. The methodology used is the linear programming, applied to the Irrigated Valley Caxito, in Bengo Province, 45 kilometers from Luanda, which has the river Dande as its source. Three scenarios concerning water price policies were tested: simple volumetric rate, variable volumetric rate and flat rate per surface. The main findings show that from the point of view of the efficient use of water in agriculture, the best results are obtained with variable volumetric rate; from the social point of view, the simple volumetric rate has the best results; the volume variable rate method proved to be the most penalizing, quickly reducing the area of most water consuming cultures, being the method in which the environmental objectives would be more readily achieved. Either methods bring negative aspects in relation to the reduction of total gross margin.

Estimativa dos coeficientes de afetação dos custos às atividades agrícolas usando a teoria da máxima entropia

This paper aims to estimate the cost allocation coefficients of agricultural activities based on incomplete information. A model to disaggregate the variable input costs based on the maximum entropy theory was developed. It was applied to the Alentejo region using data from the FADN network of 2008. Results show that entropy theory is a flexible and robust option for estimating cost allocation coefficients of agricultural activities in a context of incomplete information. Between model variants used, the model of generalized cross entropy had the best forecast capacity, once the estimated coefficients are closer to the real values.

A competitividade do regadio de Alqueva em Portugal: o caso do bloco de rega do Monte Novo

The main purpose of this paper is evaluating the competitiveness of the Alqueva irrigation project in the Alentejo region, South of Portugal. This study was based on three representative farms which were selected from one farm sample of the Monte Novo irrigation scheme. For each farm, it was developed a multi-period mathematical programming model which represents its specific skills. Results show that Common Agricultural Policy and Water Framework Directive have adverse impact on competitiveness. However, the adoption of new technological innovations and more environmental sustainable systems of agricultural production might help to mitigate those adverse impacts and promote the competitiveness of this irrigation project.

Assessing the prediction capacity of an agricultural supply positive mathematical programming model

In this paper, the calibration and prediction capacity of a supply response positive mathematical programming model (PMP) for the Alentejo region are evaluated. The model is calibrated with prices and agricultural subsidies of the base year (2000), using the specification rules of the cost function standard, Paris standard, average cost and exogenous elasticities. Then, the model is utilised for prediction of crop and livestock supply with prices and subsidies of 2004. Model results for 2000 and 2004 agricultural price and subsidies are compared, with available data, regarding optimal combination of activities to test models capacity to reproduce Alentejo agricultural sector behaviour in response to the changes in prices and agricultural policy. Results showed that the PMP model reproduces exactly the observed activity levels on the base year, whatever the rule used to specify the cost function, and that PMP is an efficient instrument to predict agricultural supply, mainly using the exogenous elasticities specification rule.