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| Registros recuperados: 18 | |
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| Severini, Simone; Cortignani, Raffaele. |
| There is a growing policy pressure to reduce water use in agriculture when this generates sufficiently large environmental benefits and increases the well-being of other water users. Several analysis investigate farmers’ response to water policy by means of mathematical programming models including Positive Mathematical Programming (PMP). The originals PMP methods refer only to activities observed in the reference period. However, under the pressure of new water policies, farmers can adjust not only their cropping patterns but also the irrigation techniques they use. In particular, they could introduce water deficit irrigation crop techniques that were not profitable in past conditions. This paper proposes an extension of the Röhm and Dabbert approach... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Positive mathematical programming; Water policies; Deficit irrigation; Crop Production/Industries. |
| Ano: 2008 |
URL: http://purl.umn.edu/44010 |
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| Paris, Quirino. |
| This paper demonstrates the existence of a unique solution of the PMP problem when both observed output quantities and limiting input prices are taken as calibrating benchmarks. This version of PMP avoids the use of a user-determined small positive number ε originally introduced for guaranteeing that the dual (shadow) price of binding input constraints be positive. Furthermore, the paper shows how to obtain endogenous output supply and input demand elasticities that match available information about them in the form of previously estimated parameters for an entire region or sector. The framework is applied to a sample of farms also for the case that admits no production for some of the crop activities. The calibrating solution is very close to the observed... |
| Tipo: Working Paper |
Palavras-chave: Positive mathematical programming; Solution uniqueness; Supply elasticities; Calibrating model; Productivity Analysis; Research Methods/ Statistical Methods; C6. |
| Ano: 2015 |
URL: http://purl.umn.edu/200491 |
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| Fragoso, Rui Manuel de Sousa; Carvalho, Maria Leonor da Silva; Henriques, Pedro Damiao de Sousa. |
| In this paper, the prescriptive capacity of different types of positive mathematical programming models applied to the Alentejo agricultural sector is analysed. Model results are compared for 2000 and 2004 agricultural price and subsidies scenarios, regarding optimal combination of activities. Thus, it is tested, on one hand, models capacity to reproduce Alentejo agricultural sector behaviour, and by the other hand, their response and adjustment capacities to changes in prices and in agricultural policy. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Positive mathematical programming; Agricultural supply; Alentejo; Research Methods/ Statistical Methods. |
| Ano: 2008 |
URL: http://purl.umn.edu/44242 |
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| Registros recuperados: 18 | |
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