11,207 research outputs found
Tractors on eBay: Differences between Internet and In-Person Auctions
Internet auction platforms are changing the face of transactions in many business sectors, including agriculture. We provide one of the first systematic examinations of the differences between internet and in-person auctions in agricultural input markets. A hedonic model estimated with used tractor transactions from Midwestern sellers pooled between eBay and in-person auctions reveals statistically distinct price surfaces for the two auction venues and predicts significantly lower prices for comparable equipment sold on eBay, though this difference is attenuated for tractors fully covered by eBay's buyer protection program and is fully absent for the most frequently traded tractor. An endogenous venue-selection model reveals that larger, more-valuable tractors are less likely to be offered on eBay, a choice that should enhance seller revenues. Furthermore, sellers in states with more valuable stocks of machinery, more frequent tractor sales, and a lower propensity to use the internet for agricultural marketing are more likely to offer tractors for sale via in-person auctions than on eBay.auctions, electronic commerce, eBay, farm equipment, hedonic models, Marketing, D44, Q13,
Willingness to pay for locally produced foods: A customer intercept study of direct market and grocery store shoppers
Increasingly, grocery stores are marketing foods differentiated as locally produced. Freshness and taste are obvious reasons for consumer preference for these goods, but also important may be home-bias. Whatever the motive, there is substantial evidence that some consumers are willing to pay premium prices for food characterized as locally produced. A customer-intercept survey and a choice experiment of food shoppers in direct markets and traditional grocery stores was analyzed using Conjoint methods to evaluate WTP for characteristics related to locally grown fresh strawberries. Our results suggest that consumers are willing to pay more for locally produced berries: Customers intercepted in grocery stores would pay an average of 64 cents more per quart, while those intercepted at direct markets would pay nearly $1.17 more per carton of strawberries that was grown locally rather than berries identified simply as "produced in the U.S." These conclusions provide a solid rationale for the existence of niche market potential for local berry producers.Consumer/Household Economics,
Strategic policies and growth: An applied model of R&D-driven endogenous growth
Cataloged from PDF version of article.We introduce and explore a general equilibrium model with R&D-driven endogenous growth, whose antecedents are the models of Romer (1990) [Romer, P.M., 1990. Endogenous technological change. Journal of Political Economy, 98, S71-102] and Grossman and Helpman (1991) [Grossman, G.M., Helpman E., 1991. Innovation and Growth in the Global Economy, The MIT Press, Cambridge]. Utilizing evidence front recent econometric studies on sources of growth, the model also accounts explicitly for cross-border technological spillovers. The model is specified and calibrated to data from Japan, and is solved to obtain both the transitional and the steady-state equilibria. We explore the effects of selective trade and R&D promotion policies on long-run growth and social welfare. The model results suggest that while a strategic trade policy has little effect on re-allocating resources into domestic R&D activities, it can significantly affect the cross-border spillovers of technological knowledge, which, in turn, stimulates growth. We find that trade liberalization may cause the growth rate to fall and lead to a loss of social welfare in the long-run, although it improves welfare in the short-run. R&D promotion policies stimulate growth by inducing private agents to allocate more resources to domestic R&D, as well as to take greater advantage of global R&D spillovers. Here, we find significantly high growth effects together with sizable gains in social welfare at low incidence to tax payers. (C) 1999 Elsevier Science B.V. All rights reserved
Storms in the tropics of Titan
Methane clouds, lakes and most fluvial features on Saturn's moon Titan have been observed in the moist high latitudes while the tropics have been nearly devoid of convective clouds and have shown an abundance of wind-carved surface features like dunes. The presence of small-scale channels and dry riverbeds near the equator observed by the Huygens probe at latitudes thought incapable of supporting convection (and thus strong rain) has been suggested to be due to geological seepage or other mechanisms not related to precipitation. Here we report the presence of bright, transient, tropospheric clouds in tropical latitudes. We find that the initial pulse of cloud activity generated planetary waves that instigated cloud activity at other latitudes across Titan that had been cloud-free for at least several years. These observations show that convective pulses at one latitude can trigger short-term convection at other latitudes, even those not generally considered capable of supporting convection, and may also explain the presence of methane-carved rivers and channels near the Huygens landing site
Gaseous argon time projection chamber with electroluminescence enhanced optical readout
Systematic uncertainties in accelerator oscillation neutrino experiments
arise mostly from nuclear models describing neutrino-nucleus interactions. To
mitigate these uncertainties, we can study neutrino-nuclei interactions with
detectors possessing enhanced hadron detection capabilities at energies below
the nuclear Fermi level. Gaseous detectors not only lower the particle
detection threshold but also enable the investigation of nuclear effects on
various nuclei by allowing for changes in the gas composition. This approach
provides valuable insights into the modelling of neutrino-nucleus interactions
and significantly reduces associated uncertainties. Here, we discuss the design
and first operation of a gaseous argon time projection chamber optically read.
The detector operates at atmospheric pressure and features a single stage of
electron amplification based on a thick GEM. Here, photons are produced with
wavelengths in the vacuum ultraviolet regime. In an optical detector the
primary constraint is the light yield. This study explores the possibility of
increasing the light yield by applying a low electric field downstream of the
ThGEM. In this region, called the electroluminescence gap, electrons propagate
and excite the argon atoms, leading to the subsequent emission of photons. This
process occurs without any further electron amplification, and it is
demonstrated that the total light yield increases up to three times by applying
moderate electric fields of the order of 3~kV/cm. Finally, an indirect method
is discussed for determining the photon yield per charge gain of a ThGEM,
giving a value of 18.3 photons detected per secondary electron
Resiliency and women exiting sex trade industry work
Summary: A qualitative approach was used to explore the experience of exiting sex trade industry work from the perspective of 19 adults formerly involved in the sex trade industry. A narrative approach to data collection was used explore the participants’ experiences of successful exiting and phenomenological analysis was employed to identify themes that reflected the ways in which participants developed resiliency throughout the exiting process.
Findings: Themes include: connection (including subthemes: survivor presence, children, and spirituality), resources (including subthemes: networks, structure and safety) and personal growth.
Significance: These themes represent women with diverse experiences in the sex trade industry, including a majority who were victimized by (internal) sex trafficking. The findings demonstrate opportunities for social work practice to address the diverse needs
of individuals exiting the sex trade industry, specifically for those who experienced sex
trafficking and sexual exploitation
An Euler Solver Based on Locally Adaptive Discrete Velocities
A new discrete-velocity model is presented to solve the three-dimensional
Euler equations. The velocities in the model are of an adaptive nature---both
the origin of the discrete-velocity space and the magnitudes of the
discrete-velocities are dependent on the local flow--- and are used in a finite
volume context. The numerical implementation of the model follows the
near-equilibrium flow method of Nadiga and Pullin [1] and results in a scheme
which is second order in space (in the smooth regions and between first and
second order at discontinuities) and second order in time. (The
three-dimensional code is included.) For one choice of the scaling between the
magnitude of the discrete-velocities and the local internal energy of the flow,
the method reduces to a flux-splitting scheme based on characteristics. As a
preliminary exercise, the result of the Sod shock-tube simulation is compared
to the exact solution.Comment: 17 pages including 2 figures and CMFortran code listing. All in one
postscript file (adv.ps) compressed and uuencoded (adv.uu). Name mail file
`adv.uu'. Edit so that `#!/bin/csh -f' is the first line of adv.uu On a unix
machine say `csh adv.uu'. On a non-unix machine: uudecode adv.uu; uncompress
adv.tar.Z; tar -xvf adv.ta
Conservation and “land grabbing” in rangelands: Part of the problem or part of the solution?
Large-scale land acquisitions have increased in scale and pace due to changes in commodity markets, agricultural investment strategies, land prices, and a range of other policy and market forces. The areas most affected are the global “commons” – lands that local people traditionally use collectively — including much of the world’s forests, wetlands, and rangelands. In some cases land acquisition occurs with environmental objectives in sight – including the setting aside of land as protected areas for biodiversity conservation. On the other hand, current trends and patterns of commercial land acquisition present a major and growing threat not just to local livelihoods and human rights, but also to conservation objectives. There is a potential opportunity here for greater collaboration between conservation interests, and local communities’ land rights interests with their supporters amongst human rights and social justice movements. This Issue Paper documents experiences from the rangelands of Mongolia, Kenya, India, Ethiopia, and other countries, which were presented at a Conference on Conservation and Land Grabbing held in London in 2013
Evaluation of Euler Fluxes for Hypersonic Heating Computations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83575/1/AIAA-41605-439.pd
Ethics, space, and somatic sensibilities: comparing relationships between scientific researchers and their human and animal experimental subjects
Drawing on geographies of affect and nature-society relations, we propose a radical rethinking of how scientists, social scientists, and regulatory agencies conceptualise human and animal participants in scientif ic research. The scientific rationale for using animal bodies to simulate what could be done in human bodies emphasises shared somatic capacities that generate comparable responses to clinical interventions. At the same time, regulatory guidelines and care practices stress the differences between human and animal subjects. In this paper we consider the implications of this differentiation between human and animal bodies in ethical and welfare protocols and practices. We show how the bioethical debates around the use of human subjects tend to focus on issues of consent and language, while recent work in animal welfare reflects an increasing focus on the affectual dimensions of ethical practice. We argue that this attention to the more-than-representational dimensions of ethics and welfare might be equally important for human subjects. We assert that paying attention to these somatic sensibilities can offer insights into how experimental environments can both facilitate and restrict the development of more care-full and response-able relations between researchers and their experimental subjects. <br/
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