3,340 research outputs found
Direct CP violation in decays as a probe for new physics
In this paper we investigate CP violation in charged decays of meson.
Particularly, we study the direct CP asymmetry of the Cabibbo favored
non-leptonic and the doubly Cabibbo-suppressed
decay mode within standard model, two Higgs doublet
model with generic Yukawa structure and left right symmetric models. In the
standard model, we first derive the contributions from box and di-penguin
diagrams contributing to their amplitudes which are relevant to the generation
of the weak phases essential for non-vanishing direct CP violation. Then, we
show that these phases are so tiny leading to a direct CP asymmetry of order
in both decay modes. Regarding the two Higgs doublet model with
generic Yukawa structure and after taking into account all constraints on the
parameter space of the model, we show that the enhanced direct CP asymmetries
can be 6 and 7 orders of magnitudes larger than the standard model prediction
for and
respectively. Finally, within left right symmetric models, we find that sizable
direct CP asymmetry of can be obtained for the decay
mode after respecting all relevant
constraints.Comment: 20 pages, 2 figures. arXiv admin note: text overlap with
arXiv:1710.0041
Premium Estimation Inaccuracy and the Actuarial Performance of the US Crop Insurance Program
This article explores the impact of the likely levels of inaccuracy associated with two main types of premium estimation methods, under different sample sizes, on the actuarial performance of the US crop insurance program. The analyses are conducted under several plausible assumptions about the insurer versus the producers’ estimates for their actuarially fair premiums. Significant differences are found due to estimation method and sample size, with the currently used procedures resulting in the worse actuarial performance. Several conclusions and recommendations are provided that could markedly reduce the amount of public subsidies needed to keep this program solvent.Agricultural Subsidies, Crop Insurance Premium Estimation, Loss-Cost Procedures, Risk Management Agency, Financial Economics,
Potential for Tradable Water Allocation and Rights in Jordan
This paper estimates the costs of buying water use rights from farmers located in the Mafraq-Azraq basin in Jordan. Farmers’ water supply curve is estimated using data gathered from a contingent valuation survey. Estimation results indicate that a total supply of 29 million m3 could be periodically purchased from farmers at an annual price of approximately JD 0.23/m3 (1 JD ≈ 0.70 U.S. dollars), or a total cost of about JD 6.8 million per year.Contingent valuation, non-parametric estimation, water supply curve, Research Methods/ Statistical Methods, Resource /Energy Economics and Policy,
Can Crop Insurance Premiums Be Reliably Estimated?
This paper develops and applies a methodology to assess the accuracy of historical loss-cost rating procedures, similar to those used by the U.S. Department of Agriculture’s Risk Management Agency (RMA), versus alternative parametric premium estimation methods. It finds that the accuracy of loss-cost procedures leaves much to be desired, but can be markedly improved through the use of alternative methods and increased farm-level yield sample sizes. Evidence suggests that the high degree of inaccuracy in crop insurance premium estimations through historical loss-cost procedures identified in the paper might be a major factor behind the need for substantial government subsidies to keep the program solvent.agricultural subsidies, crop insurance premium estimation, loss-cost procedures, Risk Management Agency, Agricultural and Food Policy, Agricultural Finance, Farm Management, Risk and Uncertainty,
ECONOMIC VALUE OF THE CARBON SINK SERVICES OF TROPICAL SECONDARY FORESTS AND ITS MANAGEMENT IMPLICATIONS
This paper explores the economic feasibility secondary forest regeneration and conservation as an alternative to help address global warming. Detailed measurements of tropical secondary forests through time, in different ecological zones of Costa Rica, are used for estimating carbon storage models. The paper addresses key issues in the international discussion about cross- and within-country compensation for carbon storage services and illustrates a method to compute/predict their economic value through time under a variety of scenarios. The procedure is applicable to other developing countries where secondary forest growth is increasingly important.Tropical Forests, Carbon Sequestration, Global Warming, Activities Implemented Jointly., Environmental Economics and Policy, Resource /Energy Economics and Policy, Q23, Q25, Q28.,
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