VIRGINIA FARMERS' SOIL CONSERVATION DECISIONS: AN APPLICATION OF TOBIT ANALYSIS

Using data from a survey of farm operators in two Virginia counties, the authors analyze farmers' soil conservation decisions. Results indicate that financial factors, including income and debt, are the most important influences on the sample farmers' use of conservation practices. Additional factors such as perception of erosion, education level, off-farm employment, and tenancy also influence conservation expenditures. Factors influencing conservation tillage acreage differ from those influencing expenditures for other conservation practices. In particular, age and race of the operator and on-farm erosion potential are significantly related to the use of conservation tillage but not other practices. These results are discussed in terms of their implications for conservation programs.Resource /Energy Economics and Policy,

SETTING THE ANIMAL WASTE MANAGEMENT POLICY CONTEXT

Livestock Production/Industries,

THE PORTER HYPOTHESIS, PROPERTY RIGHTS, AND INNOVATION OFFSETS: THE CASE OF SOUTHWEST MICHIGAN PORK PRODUCERS

The Porter Hypothesis relates the effects of environmental regulation on (a) technological innovation and (b) economic performance. Specifically, it asserts that innovation offsets can occur. These are a type of technological change that will "partially or more than fully offset the costs of complying with environmental regulation" (Porter and van der Linde, 1995, p. 98). The hypothesis has been highly debated, in part, because nomenclature has been careless. Also, the role of property rights in defining innovation offsets has been neglected. If the Porter Hypothesis has validity in agriculture, its policy implications are important. Recent changes in agro-environmental legislation provides an opportunity to more thoroughly investigate the hypothesis and its implications.Environmental Economics and Policy, Land Economics/Use, Livestock Production/Industries,

A wider audience: Turning VLBI into a survey instrument

Radio observations using the Very Long Baseline Interferometry (VLBI) technique typically have fields of view of only a few arcseconds, due to the computational problems inherent in imaging larger fields. Furthermore, sensitivity limitations restrict observations to very compact and bright objects, which are few and far between on the sky. Thus, while most branches of observational astronomy can carry out sensitive, wide-field surveys, VLBI observations are limited to targeted observations of carefully selected objects. However, recent advances in technology have made it possible to carry out the computations required to target hundreds of sources simultaneously. Furthermore, sensitivity upgrades have dramatically increased the number of objects accessible to VLBI observations. The combination of these two developments have enhanced the survey capabilities of VLBI observations such that it is now possible to observe (almost) any point in the sky with milli-arcsecond resolution. In this talk I review the development of wide-field VLBI, which has made significant progress over the last three years.Comment: Invited review at the General Assembly of the Astronomische Gesellschaf

Assessing Civic Mindedness

These models, although described using diverse language, share a worthwhile goal: to prepare American students to participate in democratic forums, even and especially in this time of economic need. Without this preparation, students may be rehearsing for work in a challenging economic environment without developing the critical skills they will need to build a new and more vibrant democratic society. In fact, the two goals are connected: As Martha Nussbaum has noted, "A flourishing economy requires the same skills that support citizenship" (2010). These skills include the ability to consider multiple angles, converse with those who hold different perspectives, and compromise to creatively solve urgent problems. Such are the habits that a liberal education engenders, and such education can help reverse our civic recession and inspire democratic engagement now and in the future

The Spectroscopic Age of 47 Tuc

High signal-to-noise integrated spectra of the metal-rich globular cluster 47 Tuc, spanning the H-gamma(HR) and Fe4668 line indices, have been obtained. The combination of these indices has been suggested (Jones & Worthey 1995, ApJ, 446, L31) as the best available mechanism for cleanly separating the age-metallicity degeneracy which hampers the dating of distant, unresolved, elliptical galaxies. For the first time, we apply this technique to a nearby spheroidal system, 47 Tuc, for which independent ages, based upon more established methods, exist. Such an independent test of the technique's suitability has not been attempted before, but is an essential one before its application to more distant, unresolved, stellar populations can be considered valid. Because of its weak series of Balmer lines, relative to model spectra, our results imply a spectroscopic ``age'' for 47 Tuc well in excess of 20 Gyr, at odds with the colour-magnitude diagram age of 14+/-1 Gyr. The derived metal abundance, however, is consistent with the known value. Emission ``fill-in'' of the H-gamma line as the source of the discrepancy cannot be entirely excluded by existing data, although the observational constraints are restrictive.Comment: 17 pages, 4 figures, LaTeX, accepted for publication in The Astronomical Journal, also available at http://casa.colorado.edu/~bgibson/publications.htm