5,570 research outputs found
Measuring the Willingness to Pay for Fresh Water Cave Diving
Fresh water springs are unique natural resources that are contained within public lands across the United States. Natural resource management on public lands generates many interesting policy issues as the competing goals of conservation, recreational opportunity provision, and revenue generation often clash. As demand for recreational cave diving sites increases, the paper provides natural resource site managers with the first statistical estimate of divers’ willingness to pay to dive fresh water cave and cavern systems. Using a contingent valuation model approach and correcting for hypothetical bias, we find that divers’ median willingness to pay for cave diving opportunities at the site of interest is approximately $68 per dive. Model results also provide evidence of diver sensitivity with respect to scope as individuals are willing to pay more for dives that are higher in quality. Key Words: Contingent Valuation Model; Willingness to Pay; Cave Diving; Scope Sensitivity
Using Revealed and Stated Preference Data to Estimate the Scope and Access Benefits Associated with Cave Diving
In a single-site travel cost model framework, revealed and stated preference data are jointly estimated to provide the first use value estimate associated with recreational cave diving. Focusing on one of Florida’s first magnitude springs, we estimate average per-person per-trip use values of approximately 1,150. Further, in an investigation of potential site quality changes, we find that divers are sensitive to scope effects with an additional cave system increasing annual per-person use values by approximately 57 in per-person annual consumer surplus. Finally, three additional model specifications are estimated and indicate that divers use different travel cost preferences when assessing their revealed and stated preference trip counts but a single preference structure to evaluate site quality changes. Key Words: Revealed and Stated Behavior; Scope Effects; Access; Travel Cost Preferences
Analyzing the Fierz Rearrangement Freedom for Local Chiral Two-Nucleon Potentials
Chiral effective field theory is a framework to derive systematic nuclear
interactions. It is based on the symmetries of quantum chromodynamics and
includes long-range pion physics explicitly, while shorter-range physics is
expanded in a general operator basis. The number of low-energy couplings at a
particular order in the expansion can be reduced by exploiting the fact that
nucleons are fermions and therefore obey the Pauli exclusion principle. The
antisymmetry permits the selection of a subset of the allowed contact operators
at a given order. When local regulators are used for these short-range
interactions, however, this "Fierz rearrangement freedom" is violated. In this
paper, we investigate the impact of this violation at leading order (LO) in the
chiral expansion. We construct LO and next-to-leading order (NLO) potentials
for all possible LO-operator pairs and study their reproduction of phase
shifts, the He ground-state energy, and the neutron-matter energy at
different densities. We demonstrate that the Fierz rearrangement freedom is
partially restored at NLO where subleading contact interactions enter. We also
discuss implications for local chiral three-nucleon interactions.Comment: 11 pages, 5 figure
PrAGMATiC: a Probabilistic and Generative Model of Areas Tiling the Cortex
Much of the human cortex seems to be organized into topographic cortical
maps. Yet few quantitative methods exist for characterizing these maps. To
address this issue we developed a modeling framework that can reveal
group-level cortical maps based on neuroimaging data. PrAGMATiC, a
probabilistic and generative model of areas tiling the cortex, is a
hierarchical Bayesian generative model of cortical maps. This model assumes
that the cortical map in each individual subject is a sample from a single
underlying probability distribution. Learning the parameters of this
distribution reveals the properties of a cortical map that are common across a
group of subjects while avoiding the potentially lossy step of co-registering
each subject into a group anatomical space. In this report we give a
mathematical description of PrAGMATiC, describe approximations that make it
practical to use, show preliminary results from its application to a real
dataset, and describe a number of possible future extensions
NASCAR Sponsorship And Shareholder Return: Some Preliminary Results
NASCAR sponsorship is a major investment for corporations that choose it as a marketing communication tool. Companies frequently spend in excess of $10 million to sponsor a car in the Nextel Cup series. This paper develops a return on investment measure for that spending using the financial market event study methodology where race day performance influence on publicly traded sponsoring firm’s stock returns is examined. Results for the 2005 NASCAR Nextel Cup season suggest that sponsorship of top 5 finishing cars generates significant positive returns for the sponsoring company shareholders
Searching for t-bar t Resonances at the Large Hadron Collider
Many new physics models predict resonances with masses in the TeV range which
decay into a pair of top quarks. With its large cross section, t-bar t
production at the Large Hadron Collider (LHC) offers an excellent opportunity
to search for such particles. We present a detailed study of the discovery
potential of the CERN Large Hadron Collider for Kaluza-Klein (KK) excitations
of the gluon in bulk Randall-Sundrum (RS) models in the t-bar t -> ell^+/- nu
b-bar bq-bar q' (ell=e, mu) final state. We utilize final states with one or
two tagged b-quarks, and two, three or four jets (including b-jets). Our
calculations take into account the finite resolution of detectors, the energy
loss due to b-quark decays, the expected reduced b-tagging efficiency at large
t-bar t invariant masses, and include the background originating from Wb-bar
b+jets, (Wb+W-bar b)+jets, W+jets, and single top + jets production. We derive
semi-realistic 5 sigma discovery limits for nine different KK gluon scenarios,
and compare them with those for KK gravitons, and a Z_H boson in the Littlest
Higgs model. We also analyze the capabilities of the LHC experiments to
differentiate between individual KK gluon models and measure the couplings of
KK gluons to quarks. We find that, for the parameters and models chosen, KK
gluons with masses up to about 4 TeV can be discovered at the LHC. The ability
of the LHC to discriminate between different bulk RS models, and to measure the
couplings of the KK gluons is found to be highly model dependent.Comment: revtex3, 27 pages, 5 tables, 6 figure
Diving Demand for Large Ship Artificial Reefs
Using data drawn from a web-based travel cost survey, we jointly model revealed and stated preference trip count data in an attempt to estimate the recreational use value from diving the intentionally sunk USS Oriskany. Respondents were asked to report their: (i) actual trips from the previous year, (ii) anticipated trips in the next year, and (iii) anticipated trips next year assuming a second diveable vessel (a Spruance class destroyer) is sunk in the same vicinity. Results from several different model specifications indicate average per-person, per-trip use values range from 750. The “bundling†of a second vessel in the area of the Oriskany to create a multiple-ship artificial reef area adds between 1,160 per diver per year in value.Artificial reefs, diving, recreation demand, combined revealed and stated preferences, non-market valuation, Institutional and Behavioral Economics, Marketing, Productivity Analysis, Public Economics, Research Methods/ Statistical Methods, Q26, Q50,
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