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| Registros recuperados: 14 | |
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| Knapp, Keith C.; Dinar, Ariel. |
| Irrigation with saline waters is a major problem in many parts of the world. Economic questions have usually been addressed using synthesized production functions and theoretically based soil salinity relations. The purpose of this paper is to estimate functions relating crop yield and salt accumulation in the soil to initial soil salinity and water quantity and quality. Crop response functions and dynamic salt balance relations are estimated from experimental data for alfalfa and cotton. The estimated functions are then used in a dynamic programming model to determine optimal water applications for different levels of initial soil salinity and crop and water prices. |
| Tipo: Journal Article |
Palavras-chave: Crop Production/Industries; Resource /Energy Economics and Policy. |
| Ano: 1986 |
URL: http://purl.umn.edu/32547 |
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| Howitt, Richard E.; Reynaud, Arnaud; Msangi, Siwa; Knapp, Keith C.. |
| In this paper we develop a positive calibrated approach to stochastic dynamic programming. Risk aversion, discount rate, and intertemporal substitution preferences of the decision-maker are calibrated by a procedure that minimizes the mean squared error from data on past decisions. We apply this framework to managing stochastic water supplies from Oroville Reservoir, located in Northern California. The calibrated positive SDP closely reproduces the historical storage and releases from the dam and shows sensitivity of optimal decisions to a decision-maker's risk aversion and intertemporal preferences. The calibrated model has average prediction errors that are substantially lower than those from the model with an expected net present value objective. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 2002 |
URL: http://purl.umn.edu/19620 |
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| Konyar, Kazim; Knapp, Keith C.. |
| Alfalfa's heavy reliance on irrigation water and its role as an alternate to program crops makes it susceptible to changes in government farm policies. This article presents a dynamic spatial equilibrium model of the California alfalfa market. The model is used to forecast alfalfa acreage, prices paid and received, and transportation flows for the short run and the long run under the base year conditions. The base year results then are compared to a situation of changing demand due to reductions in federal water subsidies and the implementation of a cotton acreage-reduction program. |
| Tipo: Journal Article |
Palavras-chave: Agricultural and Food Policy; Crop Production/Industries. |
| Ano: 1990 |
URL: http://purl.umn.edu/32500 |
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| Dinar, Ariel; Knapp, Keith C.. |
| Agricultural production in many semi-arid areas over the world is affected by poor drainage and saline conditions. Optimal agricultural management can be considerably different under these conditions than in locations where these problems do not occur. A long-run steady-state model is developed to analyse several management strategies for a farm with limited natural drainage and no access to off farm facilities. The model is applied to a representative farm in California. Under optimal management, the results suggest relatively small evaporation ponds, a reduction in water application, and little change in cropping patterns. Some drainage reuse is optimal when only variable reuse costs are considered. Returns to land and management are positive in all... |
| Tipo: Journal Article |
Palavras-chave: Land Economics/Use. |
| Ano: 1988 |
URL: http://purl.umn.edu/22920 |
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| Knapp, Keith C.; Sadorsky, Perry A.. |
| A dynamic optimization model for agroforestry management is developed where tree biomass and soil salinity evolve over time in response to harvests and irrigation water quantity and quality. The model is applied to agroforestry production in the San Joaquin Valley of California. Optimal water applications are at first increasing in soil salinity, then decreasing, while the harvest decision is relatively robust to changes in most of the underlying economic and physical parameters. Drainwater reuse for agroforestry production also appears promising: both net reuse volumes and the implied net returns to agroforestry are substantial. |
| Tipo: Journal Article |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 2000 |
URL: http://purl.umn.edu/30832 |
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| Knapp, Keith C.. |
| An OLG model with exhaustible resources and solar energy is developed, and equilibrium time paths are characterized numerically using recursive methods. For the parameter values considered, resource prices increase over time, and extractions, output, and utility decline over time until a steady-state is reached. Decreasing the intertemporal elasticity of substitution or raising consumers' subjective discount rate hastens exhaustion of the resource stock. Market equilibrium can result in much quicker use of the stock than social optimality under a constant discount rate, with consequent higher utility for early generations and lower utility for future generations in contrast to social optimality. |
| Tipo: Journal Article |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 1996 |
URL: http://purl.umn.edu/31654 |
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| Schwabe, Kurt A.; Knapp, Keith C.; Kan, Iddo. |
| Drainwater management strategies include source control, reuse, treatment, and evaporation ponds; questions of interest are efficient management, policy instruments, and sustainability. A high level of source control is indicated absent reuse due to the relatively high cost of evaporation ponds; this is accomplished largely through high uniformity/high cost irrigation systems. With reuse, the primary form of source control is reduction in land area devoted to freshwater production; the released land goes to reuse production. Reuse appears as an economically promising solution to the drainage problem. A high level of net returns is achieved while maintaining overall hydrologic balance in the system. Economic efficiency and hydrologic balance may be... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 2002 |
URL: http://purl.umn.edu/19609 |
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| Kan, Iddo; Schwabe, Kurt A.; Knapp, Keith C.. |
| Water management and reuse at the field level are analyzed under saline, limited drainage conditions. A function relating crop yield and deep percolation flows to applied water and salinity concentration is developed. This function fits simulated data well and is tractable for theoretical and empirical analysis of irrigation economics. With a single irrigation source, irrigation water for cotton and tomatoes at first increases and the decreases with salt concentration. Drain-water reuse is found to be an efficient strategy in events of high surface-water prices and costly solutions to drainage-related environmental problems. However, blending freshwater and drainage appears plausible only under surface water scarcity |
| Tipo: Journal Article |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 2002 |
URL: http://purl.umn.edu/31081 |
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| Schwabe, Kurt A.; Knapp, Keith C.. |
| A spatially dynamic programming model of nonuniform irrigation is developed to investigate the nitrogen leaching problem associated with irrigated agriculture. We evaluate the importance of temporal and spatial elements in (i) appropriately modeling the interseasonal corn production problem with nitrogen carry-over and leaching under non-uniform irrigation, and (ii) in adequately evaluating alternative policy instruments for pollution control. Comparisons of the time profiles under spatially variable nitrogen levels arising from nonuniform irrigation are provided along with an evaluation of three different price-based policy instruments for reducing nitrogen leaching. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Environmental Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/19466 |
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| Knapp, Keith C.. |
| PV-optimality in a capital-resource economy can imply decreasing utility over some portion of the time horizon. Various criteria have been proposed to maintain intergenerational equity defined as nondeclining utility, but these have some limitations and problems. This paper proposes a new welfare criteria incorporating present value to maintain efficiency, and an equity function with convex costs on declining utility. This criterion is economically efficient, time-consistent and recursive. An extension of dynamic programming to multiple value functions is developed to solve this problem. Increasing the equity weight increasingly eliminates declining portions of utility time paths. Sustainability implies increasing consumption in the early time periods and... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Growth; Environment; Intergenerational equity; Dynamic programming; Research Methods/ Statistical Methods. |
| Ano: 2006 |
URL: http://purl.umn.edu/21472 |
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| Posnikoff, Judith F.; Knapp, Keith C.. |
| Source control is one way to address salinity and drainage problems in irrigated agriculture, and reuse of drainage flows on salt-tolerant crops or trees in agroforestry production is another. A regional model of agricultural production with drainwater reuse and disposal is developed. Deep percolation flows are controlled through choice of crop areas, irrigation systems, and applied-water quantities. Crop drainwater may by reused in agroforestry production, and residual emissions are disposed of in an evaporation pond. A significant role for both source control and reuse is found. Sensitivity to various cost and revenue parameters is also analyzed. |
| Tipo: Journal Article |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 1996 |
URL: http://purl.umn.edu/31020 |
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| Registros recuperados: 14 | |
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