MODELING SPATIAL DEPENDENCE AND SPATIAL HETEROGENEITY IN COUNTY YIELD FORECASTING MODELS

The implications of ignoring potential spatial dependence in county-level yield data are discussed. Spatial dependence in a county-level yield data set is identified and methods for correcting the dependence via spatial weighting matrices and generalized least squares regression are performed. The paper also examines how the spatial dependence declines as the distance between observations increases.Productivity Analysis, Research Methods/ Statistical Methods,

Inspections To Avert Terrorism: Robustness Under Severe Uncertainty

Protecting against terrorist attacks requires making decisions in a world in which attack probabilities are largely unknown. The potential for very large losses encourages a conservative perspective, in particular toward decisions that are robust. But robustness, in the sense of assurance against extreme outcomes, ordinarily is not the only desideratum in uncertain environments. We adopt Yakov Ben-Haim’s (2001b) model of information gap decision making to investigate the problem of inspecting a number of similar targets when one of the targets may be attacked, but with unknown probability. We apply this to a problem of inspecting a sample of incoming shipping containers for a terrorist weapon. While it is always possible to lower the risk of a successful attack by inspecting more vessels, we show that robustness against the failure to guarantee a minimum level of expected utility might not be monotonic. Robustness modeling based on expected utility and incorporating inspection costs yields decision protocols that are a useful alternative to traditional risk analysis.Terrorism, Robustness, Severe Uncertainty, Port Security

ECONOMIC RISK AND THE STRUCTURAL CHARACTERISTICS OF FARM BUSINESSES

Using longitudinal panel farm-level data, this study finds that income variability may be materially influenced by farm size. Econometric results suggest that policy analyses and other considerations of the distributional effects of, and response to, income variability for commercial scale family farms may concentrate on farm size and other structural variables.risk, income variability, farm size, financial structure, Farm Management, Industrial Organization,

Economic Statistics and U.S. Agricultural Policy

Economic statistics can be used to inform policy as it is being designed, avoid policy design mistakes, or implement government programs once they are established into law. Oftentimes, statistics are used for all three purposes. This paper considers the relationships between statistics and agricultural policy in the case of the United States. We address first the broad historical picture of U.S. official economic statistics concerning agriculture, and then turn to selected examples that relate policies to economic statistics in more detail. The examples show diversity in the interplay between statistics and policy. As policies have become broader in scope, addressing not only farm commodity markets but also differences among farms and a widening set of activities on farms, policymakers have asked for more detailed information about the financial situation of individual farm businesses and households, sources of risk in farm returns, and production practices that affect the environment.Agricultural policy, Data collection and estimation, Economic history of U.S. agriculture, Agricultural and Food Policy, Q18, C8, N52,

Department of Homeland Security Science and Technology Directorate: Developing Technology to Protect America

In response to a congressional mandate and in consultation with Department of Homeland Security's (DHS) Science and Technology Directorate (S&T), the National Academy conducted a review of S&T's effectiveness and efficiency in addressing homeland security needs. This review included a particular focus that identified any unnecessary duplication of effort, and opportunity costs arising from an emphasis on homeland security-related research. Under the direction of the National Academy Panel, the study team reviewed a wide variety of documents related to S&T and homeland security-related research in general. The team also conducted interviews with more than 200 individuals, including S&T officials and staff, officials from other DHS component agencies, other federal agencies engaged in homeland security-related research, and experts from outside government in science policy, homeland security-related research and other scientific fields.Key FindingsThe results of this effort indicated that S&T faces a significant challenge in marshaling the resources of multiple federal agencies to work together to develop a homeland security-related strategic plan for all agencies. Yet the importance of this role should not be underestimated. The very process of working across agencies to develop and align the federal homeland security research enterprise around a forward-focused plan is critical to ensuring that future efforts support a common vision and goals, and that the metrics by which to measure national progress, and make changes as needed, are in place

The Importance of Phase in Nulling Interferometry and a Three Telescope Closure-Phase Nulling Interferometer Concept

We discuss the theory of the Bracewell nulling interferometer and explicitly demonstrate that the phase of the "white light" null fringe is the same as the phase of the bright output from an ordinary stellar interferometer. As a consequence a "closure phase" exists for a nulling interferometer with three or more telescopes. We calculate the phase offset as a function of baseline length for an Earth-like planet around the Sun at 10 pc, with a contrast ratio of $10^{-6}$ at 10 $\mu$m. The magnitude of the phase due to the planet is $\sim 10^{-6}$ radians, assuming the star is at the phase center of the array. Although this is small, this phase may be observable in a three-telescope nulling interferometer that measures the closure phase. We propose a simple non-redundant three-telescope nulling interferometer that can perform this measurement. This configuration is expected to have improved characteristics compared to other nulling interferometer concepts, such as a relaxation of pathlength tolerances, through the use of the "ratio of wavelengths" technique, a closure phase, and better discrimination between exodiacal dust and planets

Professional decision making and women offenders : containing the chaos?

This article draws on the findings from research undertaken in south-east Scotland in 2008 which sought to identify the characteristics of female offenders and to document the views of policy makers and practitioners regarding the experiences of women involved in the Scottish criminal justice system. Despite Scotland having retained a stronger 'welfare' focus than elsewhere in the UK (e.g. McAra, 2008), this is not reflected in the treatment of women who offend, with the rate of female imprisonment having almost doubled in the last ten years and community based disposals falling short of a welfare-oriented system. This article explores why the treatment that women offenders receive in the criminal justice system may be harsh and disproportionate both in relation to their offending and in relation to the treatment of men. It is argued that interventions with women need to be initiated earlier in their cycle of offending and at an earlier stage in the criminal justice process but also that the wide-ranging health, welfare, financial and behavioural needs of women who offend cannot be met solely within an increasingly risk-averse and punitive criminal justice environment

Creation of Skyrmions in a Spinor Bose-Einstein Condensate

We propose a scheme for the creation of skyrmions (coreless vortices) in a Bose-Einstein condensate with hyperfine spin F=1. In this scheme, four traveling-wave laser beams, with Gaussian or Laguerre-Gaussian transverse profiles, induce Raman transitions with an anomalous dependence on the laser polarization, thereby generating the optical potential required for producing skyrmions.Comment: 5 pages, 2 figures, RevTe