AGRICULTURAL LAND VALUES AND FUTURE LAND DEVELOPMENT

We develop a theoretical model of land prices and urban expansion and derive a reduced-form expression for agricultural land values. This result dictates the specification of our econometric model in terms of variable choice and functional form. We find strong support for the model in an application to New York.Land Economics/Use,

The Search for Optimal Management of Head Injury

Head injuries of sufficient severity to bring the patient to a hospital occur in more than one per hundred of the population every year. The toll in death and disability is staggering: the majority of patients are young wage-earners with families so that the total socio-economic burden can hardly be guessed at. Much emphasis is laid on the concept that physical disruption of neurons in the brain is not a reversible process and that regeneration within the nervous system to the point of functional recovery does not occur; however, this rather dismal view of head injury is at variance with the facts. Most cases of head injury reaching the hospital are associated with relatively minor degrees of primary brain damage from which full functional recovery may be expected even though there are minor residual neurological signs. The major problem for the physician treating head injuries in hospitals is that secondary complications may supervene and change a relatively minor head injury case into a major disability problem or even a fatality. For the management of head injury considerable emphasis should be laid on the prevention of secondary complications; such an approach is outlined in this article

Estimating Willingness to Pay Using a Polychotomous Choice Function: An Application to Pork Products with Environmental Attributes

Bid data from a Vickrey auction for pork chops with embedded environmental attributes were analyzed. It was found that approximately 62% of the participants had a positive WTP for the most "environmentally friendly" package of pork. Thirty percent of the participants had no WTP, and 8% had a negative WTP. A polychotomous choice model was used to accommodate data having an anchoring point within the distribution of the data. Standard variables found in the WTP literature coupled with this model were used to predict participants who were premium payers and non-premium payers using an estimated ordered probit equation.anchoring points, environmental attributes, ordered probit, polychotomous choice functions, pork, Vickrey auction, willingness to pay, Consumer/Household Economics, Demand and Price Analysis,

ESTIMATING WILLINGNESS-TO-PAY USING A POLYCHOTOMOUS CHOICE FUNCTION: AN APPLICATION TO PORK PRODUCTS WITH ENVIRONMENTAL ATTRIBUTES

This paper utilizes a polychotomous choice function to investigate the relationship between socioeconomic characteristics and willingness-to-pay for embedded environmental attributes. Specifically, a two-stage estimation procedure with an ordered probit selection rule is used to predict the premium payers and the magnitude of the premium they are willing to pay.Research Methods/ Statistical Methods,

WASP-12b as a prolate, inflated and disrupting planet from tidal dissipation

The class of exotic Jupiter-mass planets that orbit very close to their parent stars were not explicitly expected before their discovery. The recently found transiting planet WASP-12b has a mass Mp = 1.4(+/-0.1) Jupiter masses (MJ), a mean orbital distance of only 3.1 stellar radii (meaning it is subject to intense tidal forces), and a period of 1.1 days. Its radius 1.79(+/- 0.09) RJ is unexpectedly large and its orbital eccentricity 0.049(+/-0:015) is even more surprising as such close orbits are in general quickly circularized. Here we report an analysis of its properties, which reveals that the planet is losing mass to its host star at a rate ~ 10^-7 MJ yr^-1. The planets surface is distorted by the stars gravity and the light curve produced by its prolate shape will differ by about ten per cent from that of a spherical planet. We conclude that dissipation of the stars tidal perturbation in the planets convective envelope provides the energy source for its large volume. We predict up to 10mJy CO band-head (2.292 micron) emission from a tenuous disk around the host star, made up of tidally stripped planetary gas. It may also contain a detectable resonant super-Earth, as a hypothetical perturber that continually stirs up WASP-12b's eccentricity.Comment: Accepted to Nature, 14 pages, 1 figur

AN ALTERNATIVE APPROACH TO DETERMINING THE ELASTICITY OF EXCESS DEMAND FACING THE UNITED STATES

The United States embarked on a policy assuming excess demands for commodities are elastic. Some analysts question the success of that policy and argue that excess demands for farm commodities are inelastic. The controversy is deepened because the two traditional techniques for determining excess demand elasticities yield opposing estimates. We use an alternative technique based on observed variation in commodity prices, production, and use. The point estimates show excess demands for wheat, coarse grains, soybeans, rice, and cotton are elastic. However, a one-sided bootstrap test cannot reject the null hypothesis that the excess demands for wheat, coarse grains, and soybeans are inelastic.Demand and Price Analysis,

Notes on a new mealybug (Hemiptera: Coccoidea: Pseudococcidae) pest in Florida and the Caribbean : the papaya mealybug, Paracoccus marginatus Williams and Granara de Willink

Paracoccus marginatus Williams and Granara de Willink, here called the papaya mealybug, was first detected in the United States in Hollywood, Florida in 1998. By the end of 1998 it was found in four localities in the state and has since spread to nine localities in five counties. This mealybug appears to have moved through the Caribbean area since its 1994 detection in the Dominican Republic. The pest is reported to cause serious damage to tropical fruit, especially papaya, and has been detected most frequently, in Florida, on hibiscus. It is now known from Antigua, Belize, the British Virgin Islands, Costa Rica, Guatemala, Mexico, Nevis, Puerto Rico, St. Barthelemy, St. Kitts, St. Martin, and the US Virgin Islands. Hosts include: Acacia sp.(Luguminosae), Acalypha sp.(Euphorbiaceae), Ambrosia cumanensis (Compositae), Annona squamosa (Annonaceae), Carica papaya (Caricaceae), Guazuma ulmifolia (Sterculiaccea), Hibiscus rosa-sinensis (Euphorbiaceae), Hibiscus sp. (Euphorbiaceae), Ipomoea sp. (Convolvulaceae), Manihot chloristica (Euphorbiaceae), Manihot esculenta (Euphorbiaceae), Mimosa pigra (Lugiminosae), Parthenium hysterophorus (Compositae), Persea americana (Lauraceae), Plumeria sp. (Apocynaceae), Sida sp. (Malvaceae), Solanum melongena (Solanaceae). The species is believed to be native to Mexico andlor Central America

Impact of Farmland Preservation Programs on the Rate of Urban Development

Due to high losses of agricultural land in urbanizing areas over the past several years, state and local governments have adopted zoning regulations, right-to-farm ordinances, preferential property tax programs, and other means to protect agricultural land resources. Critics of the farmland preservation efforts note that these programs may only delay the ultimate conversion of farmland to urban uses and may simply shift urban development to neighboring areas (positive spillover effects). An alternative means of permanently protecting farmland is provided by purchase of development rights (PDR) programs, which enroll acreage from landowners who voluntarily sell the development rights to their farmland. Although ownership and all other property rights are retained by the owner, the option to develop the land for urban uses is removed from the current and all subsequent landowners. The purpose of this paper is to develop an empirical model of the impact of PDR programs on urban land development rates. To estimate the empirical model, we form a dependent variable based on county level rates of urban development from the USDA National Resources Inventory (NRI) data base for nine states in the Northeast US that have adopted farmland protection measures during the sample period (1982-1997). The set of explanatory variables include dummy variables for the existence of an active PDR program in the county and active PDR programs in adjacent counties plus measures of demographics, farm returns, population growth, income, and site-specific factors gathered from several sources (e.g., Census of Agriculture, Census of Population, and USDA). The model is estimated using the ordinary least squares technique. Two key policy-relevant hypotheses: (1) PDR programs did not reduce the rate of urban development and (2) PDR programs did not induce positive spillover effects on neighboring counties. The test results suggest that PDRs may have had important more significant impact in the earlier years and did not cause positive spillover effects.Land Economics/Use,

Product Life Cycles and Innovation in the US Seed Corn Industry

The purpose of this study is to evaluate potential changes in the length of product life cycles in the US seed corn industry. We use the observed survival time on the market for hybrids sold during 1997-2009 to conduct a survival analysis. Our empirical results show that the expected lifetimes for corn hybrids with single biotech traits are 5-15% longer than for hybrids with multiple (stacked) traits, and the expected lifetimes for conventional corn are 13-17% longer than stacked hybrids. Also, the product life cycles for all types of hybrids have decreased over the past twelve years (especially after 2004), but the rate of decline is roughly similar across hybrid types. Based on this evidence, we conclude that the shorter product life cycles are closely linked to the accelerated levels of biotech product innovation in the US seed corn industry over the period of analysis.accelerated failure time, biotechnology, product life cycle, survival analysis, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies, Research Methods/ Statistical Methods, Risk and Uncertainty,

Product Life Cycles and Innovation in the US Seed Corn Industry

The purpose of this study is to evaluate potential changes in the length of product life cycles in the US seed corn industry. We use the observed survival time on the market for hybrids sold during 1997-2009 to conduct a survival analysis. Our empirical results show that the average lifetimes of conventional and biotech corn hybrids have decreased over the last twelve years at similar rates and that the rate of decline in the life cycle length increased since 2004. We also find that the shorter product life cycles are closely linked to the accelerated levels of biotech product innovation in the US seed corn industry observed over the period of the analysis.Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,