The Optimal Intertemporal Management of the Soil and Phosphorus and the Equilibrium in Economic and Biophysical Models

The paper proposes the use of meta models to determine the optimal intertemporal management of soil and phosphorus losses from agricultural land. This approach allows finding a equilibrium of the economic and biophysical system simultaneously. In contrast to the existing literature the model takes account of nonlinear relationships and of a large number of agricultural activities. The mathematical problems arising from this complex setup are addressed and the model is solved numerically. The results show that the second best policy in form of soil protection scores is highly inefficient, while another second best policy in form of land-use taxes is nearly as efficient as the first best policy.Soil erosion, Phosphorus runoffs, Land-use tax, Soil protection scores, Dynamic optimization, Resource /Energy Economics and Policy,

Technology Adoption by Heterogeneous Producers to Regulate a Stock Externality

This paper presents a framework to determine optimal resource allocation over time for the production of a good by heterogeneous producers who generate a stock externality. We analyze the optimal intertemporal and quality-specific combination of abatement strategies at the source given by a change in the intensity of production and in the chosen technology, and/or removal of existing pollution stock. The results show how the specifications of the production and the emission functions affect technology adoption and the design of the optimal intertemporal combination of source and stock abatement strategies. Moreover, the paper shows that regulation at the intensive margin cannot be considered as a substitute for a regulation at the extensive margin. The paper employs the so-called two-stage solution approach for solving the resulting quality distributed-intertemporal optimal control problem.Research Methods/ Statistical Methods,

Optimal growth and land preservation

A model of optimal economic growth with a constant population subject to a constraint on the availability of land is presented. It takes account of the dual character of land as a production factor and as a consumption good (environmental amenities) by determining the optimal intertemporal allocation of land between productive and recreational uses. An extension of the analysis for the case of a growing population with endogenous growth based on human capital accumulation shows that if the rate of discount is not very low then there exists a set of balanced growth paths compatible with a constant allocation of land. En este trabajo se presenta un modelo de crecimiento económico óptimo con una población constante sujeto a una restricción sobre la disponibilidad de tierra. En el modelo se tiene en cuenta el carácter dual de la tierra como factor productivo y como bien de consumo para usos recreacionales y se determina cual es la asignación intertemporal óptima de la tierra entre estos dos usos. En la segunda parte del trabajo, se presenta una extensión del análisis para el caso de una población creciente con crecimiento endógeno basado en la acumulación de capital humano y se demuestra que si la tasa de descuento no es muy pequeña existe un conjunto de sendas de crecimiento equilibrado compatibles con una asignación constante de la tierra.Crecimiento óptimo, asignación intertemporal de la tierra, preservación medioambiental, crecimiento de la población, crecimiento endógeno, capital humano Optimal growth, intertemporal land allocation, environmental preservation, population growth, endogenous growth, human capital

Determining the economic gains from regulation at the extensive and intensive margins

Among the second-best approaches for the regulation of pollution, little attention has been paid to the distorting effect of intensive margin policies on the extensive margin. This article shows, within a dynamic framework, that regulation of the intensive margin has to be complemented by regulation of the extensive margin. Depending on the elasticity of the pollution function with respect to nitrogen use, the appropriate regulation at the extensive margin is zero, a tax or a subsidy. We show empirically that combining a nitrogen tax with land-use taxes is about 18 per cent more cost efficient than a nitrogen tax alone and 58 per cent more efficient than off-site abatement in the form of groundwater treatmen

Eficiencia de las reglas de asignación de agua en el regadío: Asignación a través de mercados, de la regla proporcional y de la regla uniforme

[EN] In this paper, the introduction of three different methods for the assignment of water in agriculture is simulated in order to compare its economic efficiency for the case of an irrigated area located in the central Ebro Valley. Apart from the currently applied proportional system, water markets have been simulated along with the uniform rule, developed in social choice theory. The results show that although the water market achieves the best results in all cases, the uniform rule can be an interesting alternative to current management methods if water assignments are at regular levels, while in the case of severe water shortage; markets offer a clearer advantage with regard to any other method. The results also show that higher levels of heterogeneity between firms and high water prices situate the uniform rule in a more favorable situation then the currently applied proportional system.[ES] En el presente trabajo se simula la introducción de diferentes métodos de reparto del agua en la agricultura, y se aplican a una zona de regadío del valle central del Ebro. En concreto, se han escogido tres métodos diferentes de asignación con el fin de comparar su eficiencia económica. Además del actual sistema proporcional y el sistema de mercado, se simulará la introducción de la regla de reparto uniforme, desarrollada en la teoría de la elección social. Los resultados permiten concluir que aunque el mercado de agua conduzca a mejores resultados globales en todos los casos, la regla uniforme puede resultar una alternativa interesante cuando las dotaciones de agua se encuentran en el intervalo habitual, mientras que en situaciones de escasez severa de agua, el mercado presenta una ventaja más clara con respecto a cualquier otro sistema de asignación. Asimismo, los resultados demuestran que los niveles superiores de heterogeneidad entre los usuarios y altos precios administrativos del agua representan situaciones más ventajosas para la aplicación de la regla de asignación uniforme en comparación con el actual sistema proporcional.Goetz, R.; Martínez, Y.; Rodrigo, J. (2005). Efficiency of the water assignment rules in irrigation: Assignment by market, proportional rule and uniform rule. Economía Agraria y Recursos Naturales - Agricultural and Resource Economics. 5(9):115-138. doi:10.7201/earn.2005.09.05SWORD1151385

Nonpoint source pollution, space, time and asymetric information - a deposit refund approach

The incorporation of space allows the establishment of a more precise relationship between a contaminating input, a contaminating byproduct and emissions that reach the final receptor. However, the presence of asymmetric information impedes the implementation of the first-best policy. As a solution to this problem a site specific deposit refund system for the contaminating input and the contaminating byproduct are proposed. Moreover, the utilization of a successive optimization technique first over space and second over time enables definition of the optimal intertemporal site specific deposit refund syste

THE ECONOMICS OF LAND-ZONING

Land-use restrictions are frequently applied to separate polluting from non-polluting activities. In contrast to the existing literature, we incorporate spatial and intertemporal aspects of the problem simultaneously and determine the border of the zones endogenously. The results, based on a two-stage optimization method, show that non-spatially differentiated Pigouvian taxes on the final emissions are able to establish the socially optimal outcome. Second-best instruments alone, such as a spatially differentiated tax on inputs or outputs are not able to support the socially optimal outcome and need to be complemented by land-zoning or land-use taxes. We compare the efficiency of different spatial environmental policies such as land-use taxes or land zoning. The necessary changes required to transform a spatially optimal, yet static, environmental policy into an intertemporally and spatially optimal environmental policy are presented and discussed

The Optimal Intertemporal Management of the Soil and Phosphorus and the Equilibrium in Economic and Biophysical Models

The paper proposes the use of meta models to determine the optimal intertemporal management of soil and phosphorus losses from agricultural land. This approach allows finding a equilibrium of the economic and biophysical system simultaneously. In contrast to the existing literature the model takes account of nonlinear relationships and of a large number of agricultural activities. The mathematical problems arising from this complex setup are addressed and the model is solved numerically. The results show that the second best policy in form of soil protection scores is highly inefficient, while another second best policy in form of land-use taxes is nearly as efficient as the first best policy