Accuracy of Trace Formulas

Using quantum maps we study the accuracy of semiclassical trace formulas. The role of chaos in improving the semiclassical accuracy, in some systems, is demonstrated quantitatively. However, our study of the standard map cautions that this may not be most general. While studying a sawtooth map we demonstrate the rather remarkable fact that at the level of the time one trace even in the presence of fixed points on singularities the trace formula may be exact, and in any case has no logarithmic divergences observed for the quantum bakers map. As a byproduct we introduce fantastic periodic curves akin to curlicues.Comment: 20 pages, uuencoded and gzipped, 1 LaTex text file and 9 PS files for figure

Temporal and Spatial Evaluation of Soil Conservation Policies

Contained in this paper are estimates of the benefits and costs of alternative soil conservation policies in a spatially and temporally consistent framework. The policies considered are implementation of soil conservation practices with an objective of reducing erosion to a site\u27s tolerance level and a policy with an objective of a voluntary 50 percent reduction of conventional tillage. Costs and erosion benefits of these two policies are compared with those obtained from CRP

An Economic and Environmental Evaluation of Farm Bill Policy Options Using the CEEPES-FAPRI Modeling System

This report estimates the economic and environmental trade-offs of the 1995 Farm Bill policy options evaluated by FAPRI. Assessments are provided for the 1995 FAPRI baseline, 25 percent Normal Flex, and the Revenue Assurance program. The authors describe the modeling systems and the CEEPES-FAPRI linkage, delineate the policy options and their likely economic and environmental impacts, and discuss predicted economic and environmental impacts of these policy options

The House and Senate Visions of a CRP Renewal: An Appraisal of the Likely Efficiency Gains

Analysts who have studied how to increase the efficiency of the CRP agree that one simple step can result in dramatic gains; enroll only land with high environmental benefit-to-cost ratios. Too much of current CRP land was brought in with very low ratios, either because the contract rental rates were set too high, or the land offered too few environmental benefits

Using the Hadamard and related transforms for simplifying the spectrum of the quantum baker's map

We rationalize the somewhat surprising efficacy of the Hadamard transform in simplifying the eigenstates of the quantum baker's map, a paradigmatic model of quantum chaos. This allows us to construct closely related, but new, transforms that do significantly better, thus nearly solving for many states of the quantum baker's map. These new transforms, which combine the standard Fourier and Hadamard transforms in an interesting manner, are constructed from eigenvectors of the shift permutation operator that are also simultaneous eigenvectors of bit-flip (parity) and possess bit-reversal (time-reversal) symmetry.Comment: Version to appear in J. Phys. A. Added discussions; modified title; corrected minor error

Program Participation and Farm-Level Adoption of Conservation Tillage: Estimates from a Multinomial Logit Model

Over the past decade, conservation compliance has reduced soil erosion. What will happen to these erosion benefits if commodity programs are eliminated or if the subsidy level is greatly reduced? This study investigates whether there will be a significant decline in the amount of acreage on which conservation practices are adopted if future farm program benefits are not tied to conservation compliance

CRP Targeting for Wildlife Habitat: A New Indicator Using the 1992 National Resources Inventory

Congress has wrestled with the issue of which land should be enrolled in a renewal of the Conservation Reserve Program (CRP), considering that benefits to wildlife from CRP are substantial. This paper evaluates the amount of land that may qualify for CRP enrollment in order to provide high-value wildlife habitat and to present the potential enrollment costs. The assessment is based on a wildlife habitat indicator developed from the National Resources Inventory conducted by the Natural Resources Conservation Service

The Economic, Environmental, and Fiscal Impacts of a Targeted Renewal of Conservation Reserve Program Contracts

CRP (Conservation Reserve Program) renewal may depend on improved targeting of payments to maintain a significant portion of existing environmental and farm benefits at a reduced program cost. The authors consider three alternative renewal criteria: renewal of least expensive land first, renewal of most environmentally sensitive land first, and renewal of land according to the cost per unit of environmental benefit offered

Conservation Tillage and Farm Programs

One of the major environmental initiatives of current commodity programs is Conservation Compliance, a provision that requires highly erodible land to be cropped according to a locally approved conservation plan