Regulating Nonpoint Source Pollution Under Heterogeneous Conditions

Abstract

Because of difficulties in measuring effluent from nonpoint pollution, proposals for regulating agricultural runoff often suggest instruments applied to inputs or management practices. When pollution functions vary across sources, uniform input instruments cannot achieve a least-cost pollution reduction, but efficient instruments may be difficult to administer. In this paper we analyze lettuce production on two soils in California's Salinas Valley to consider empirical costs associated with uniform input taxes and regulations. The results suggest that uniform instruments may not be costly relative to an efficient baseline. Though taxes are more efficient, farmers have higher profits with regulations.

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

“…Así, se ha optado por modelizar de una forma sencilla la existencia de cinco explotaciones con funciones de producción que difieran entre sí en un rango amplio (entre un 5 y un 30%), con el fin de abarcar un conjunto mayor de situaciones posibles. De esta forma se trata de comprobar cómo Thomas y Boisvert (1994) y Helfand y House (1995. 6 Los principales parámetros que determinaron estas diferencias son la capacidad de retención de agua, la eficiencia de riego y la conductividad eléctrica (Martínez y Albiac, 2005).afecta el grado de heterogeneidad a los resultados de las distintas reglas de asignación.…”

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“…To include these effects in the previous model, it would be sufficient to come up with a water damage function for society, add it to the objective function of the model, and proceed with maximization as usual, calculating optimal taxes that would induce polluters to act efficiently. 8 This could easily be done if the water damage function was known. Since it generally isn't, an alternative is to impose existing quality requirements on the management problem.…”

“…Helfand [7] and Helfand and House [8] analyse problems with input-based policies and compare them to emissions-based ones, noting that the latter are more difficult to implement in the nonpoint pollution case due to the frequent unobservability of emissions. The implementation of emissions taxes is even less attractive in the joint quantity/quality dynamic model because water has to be taxed anyway due to the scarcity problem.…”

“…Xepapadeas [22] presents such incentives for the case of a dynamic pollutant accumulation model with imperfect monitoring. Given implementation difficulties, there is also some work in the literature evaluating suboptimal pollution control instruments (see Shortle and Dunn [20], Larson et al [9], Helfand and House [8], and Mapp et al [11]). This paper uses a dynamic resource management perspective to show how an optimal policy takes into account effects on water stock as well as on its quality.…”

“…However, this effect could be negative, at least for some range of w, if other roles of water were considered, namely its complementarity with polluting inputs in the production of y (for instance, in agriculture, water allows plants to absorb nitrogen and phosphorus more efficiently decreasing the presence of these elements in topsoil) and its own dilution effect (if all the contaminant load is already being carried down, the addition of extra water will improve the quality of the leachates that reach the aquifer). Examples of pollution production functions for nitrates in agriculture can be found in Vickner et al [21], Larson et al [9], and Helfand and House [8]. Following the contamination literature (see Yadav [24] for nitrates, Anderson et al [1] for pesticides), it is assumed that there is a constant natural decay rate for the pollutant, so that contamination would evolve according to:…”