The Provision Point Mechanism and Scenario Rejection in Contingent Valuation

The provision point mechanism mitigates free-riding behavior in economic experiments. In two contingent valuation method surveys, we implement the provision point design. We ask respondents for their perceptions about the success of the provision point mechanism. We find that respondents who believe that the provision point would not be met are more likely to say no to a contingent valuation dichotomous choice question. The scenario rejection that arises may result in biased willingness-to-pay estimates.provision point mechanism, contingent valuation, willingness to pay, public goods, Environmental Economics and Policy,

Convection driven by temperature and composition flux with the same diffusivity

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Geophysical & Astrophysical Fluid Dynamics 111 (2017): 229-248, doi:10.1080/03091929.2017.1333608.Temperature, pressure, and composition determine density of fluids within the earth, the ocean, our atmosphere, stars and planets. In some cases, variation of composition component C competes equally with temperature T to determine buoyancy-driven flow. Properties of two-dimensional cellular convection are calculated with density difference between top and bottom boundaries determined by difference of temperature T (Dirichlet boundary conditions, quantified by Rayleigh number Ra that is positive destabilising), fluxes of C (Neumann boundary conditions quantified by Raf that is positive stabilising), and Prandtl number Pr. Numerical solutions in a 2-dimensional rectangular chamber are analysed for Prandtl numbers Pr=1,∞. For Ra and Raf>0 and Raf above approximately 300, subcritical instability separates T-driven convection from C-dominated stagnation. The flow is steady but a sudden change in Ra or Raf produces decaying pulsations to the new flow. A boundary layer solution for rapid flow exists in which T, which has the Dirichlet condition, is more sensitive to flow speed than C with the Neumann condition. A new type of pulsating flow occurs for Ra and Raf<0. The pulsations are characterised by slow flow with gradually strengthening compositional plumes in a thermally stratified flow interrupted by rapid flow with gradually weakening compositional plumes. In this slow speed range, C is more sensitive to speed than T

Dimensions of continents and oceans – water has carved a perfect cistern

© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 467 (2017): 18-29, doi:10.1016/j.epsl.2017.03.017.The ocean basins have almost exactly the correct surface area and average depth to hold Earth’s water. This study asserts that three processes are responsible for this. First, the crust is thickened by lateral compression from mountain formation. Second, Earth’s continental crust is leveled by erosion. Third, due to the efficiency of erosion, the average elevation is a few hundred meters above sea level. A theoretical fluid model, suggested partly by laboratory experiments, includes an ocean of specified depth. The resulting continents are tabular (that is, their elevation view is rectangular). The surface lies above sea level, contributing to a well-known double maximum in Earth’s elevation corresponding to continents and ocean basins. Next, a simple hydrostatic balance between continent and ocean gives average depth and area of present oceans and continents within 33%. Further calculations with a suitable correction to fit present Earth cover a wide range of possible crust volumes for earlier Earth. With the present water volume, ocean area always exceeds 25% of the globe. For all possible water volumes, average continental crust thickness always exceeds 23.4 km. This may explain why cratons have thicknesses comparable to younger crust so that they are found on Earth’s surface today. Therefore, mountain building, and erosion have enabled water to carve its own cistern in the form of the accumulated ocean basins. The wide range of areas and depths of oceans and continents found here can constrain models of early earth. Similar calculations can be done for earthlike planets as well

Rotating hydraulic control : 1997 summer study program in geophysical fluid dynamics

Rotating Hydraulic Control was the topic of the thirty ninth year of the Geophysical Fluid Dynamics (GFD) program at the Woods Hole Oceanographic Institution. This theme was principally centered about those nonlinear problems in which either a free surface or internal stratification is so modified by flow that it acts to choke off increased flux as the forcing is increased. It is a peculiar form of convection, which shares many constraints with more general buoyancy driven motion but which has its own internal limits. Lectures and seminars were given by GFD staff and visitors, most of whom are founders of this young field of study. This volume contains notes from the talks given by the principal lecturers and written reports on the research projects cared out by the ten student fellows. The volume, therefore, summarizes a sizable percentage of the present understanding of the topic of Rotating Hydraulic Control.Funding was provided by the National Science Foundation through Grant No. OCE-9314484 and the Office of Naval Research through Grant No. ONR-N00014-97-1-0934

The similarity solution for turbulent mixing of two-layer stratified fluid

© 2008 The Author. This is an open-access article distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Environmental Fluid Mechanics 8 (2008): 551-560, doi:10.1007/s10652-008-9076-5.Experiments are reviewed in which a two-layer salt-stratified tank of water was mixed by turbulence. The density profile began as a single step and evolved to a smooth mixed profile. The turbulence was generated by many excursions of a horizontally moving vertical rod with Richardson number Ri > 0.9 and Reynolds Number Re > 600. There was almost perfect collapse of all the profiles to one universal profile as a function of a similarity variable. We develop a theoretical model for a simple mixing law with a buoyancy flux that is a function of internal Richardson number Rii. A similarity equation is found. A flux law that increases with small Rii and decreases with large Rii is considered next. Since no analytical solution is known, the similarity concept is tested by numerically integrating the equations in space and time. With buoyancy flux monotonically increasing with internal Richardson number, the similarity approach is valid for a profile starting from a slightly smoothed step. However, a shock forms for a mixing law with higher initial Rii (so that buoyancy flux decreases with Richardson number) and the similarity approach is invalid for those initial conditions

Fluid flow with three upstream configurations in freezing tubes

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Whitehead, J. A. Fluid flow with three upstream configurations in freezing tubes. Journal of Geophysical Research: Earth Surface, 126(6), (2021): e2020JF005969, https://doi.org/10.1029/2020JF005969.The accumulation of frozen liquid around a central passageway of melt as it flows through a freezing region can make calculations very challenging. To both illustrate and to quantify some of these challenges from freezing, a model equation is developed. It simplifies the solution of Holmes (2007, https://gfd.whoi.edu/wp-content/uploads/sites/18/2018/03/MHolmesGFDReport_30151.pdf) for low Reynolds number single component liquid flow through a long tube that has a wall kept at subfreezing temperature. This model equation is used in conjunction with three different upstream configurations, each with parameters expressing their behavior. Analytical and numerical results give the parameters that have criteria for: the freezing of a compressible upstream reservoir that includes oscillatory behavior; the freezing of flow fed through a constriction with a large upstream pressure, just like a dripping water faucet during winter; the evolution of flow in multiple tubes connected by an upstream manifold, where some tubes end up with full flow and others freeze shut. Numerical runs with 1,000 tubes give a formula for the spacing between actively flowing (non-frozen) tubes over wide ranges of the two upstream parameters (flow rate and manifold resistance). Results have implications in various areas in earth science. Some are: oscillatory and freezing shut criteria for flow of magma from a compressible region, a criterion for wintertime ice accumulation at natural springs, and the spacing between volcanos.Emeritus funds are provided by Woods Hole Oceanographic Institution

Benefit Transfer in the Field: Measuring the Benefits of Heterogeneous Wetlands using Contingent Valuation and Ecological Field Appraisals

Wetlands have functional values that may extend beyond traditional real estate values. This paper uses contingent valuation and ecological field assessments to place heterogeneous values on heterogeneous wetlands. Wetland functions evaluated are water quality, habitat, recreation, storing floodwaters and erosion abatement. The model used incorporates the public value of wetland functions and adds that value to the common local appraisal cost. We use a “percentage willingness-to-pay” value elicitation question in which respondents are asked about the percentage amount that the state government should pay over and above market value to purchase and preserve a wetland function. These values are then mapped into an ecological matrix to value the wetland as a whole. We show how these values can be applied in the field. Key Words: wetlands, appraisal, evaluation, mitigation, contingent valuation methodLength:

Linking Recreation Demand and Willingness to Pay with the Inclusive Value: Valuation of Saginaw Bay Coastal Marsh

In this paper we propose an alternative model for linking revealed preference and stated preference models of recreation when a single travel cost measure is difficult to obtain. We show that this model can be used to test convergent validity and offers an alternative scope test that does not rely on split-sample contingent valuation scenarios. Our results are mixed. In three of four models the inclusive value is negatively related to the willingness to donate but unrelated to the willingness to pay. This result suggests that recreation nonusers hold nonuse values while recreation users do not hold nonuse values.

The Willingness to Pay to Remove Billboards and Improve Mountain Views

We use the contingent valuation method to measure the amount citizens are willing to pay to improve mountain-view aesthetics through the removal of billboards. Our approach addresses both the perceived property rights as well as the perceptions of the status quo in the southern Appalachian Mountains. We find that individuals who retire to the mountains have different preferences for land use and mountain views than individuals who have ancestors who lived in Watauga County. In the aggregate, we find that citizens are willing to pay up almost one-half million dollars to remove billboards from Watauga County roadsides. This study provides insights to the debate surrounding land use in the mountains.

Green vs. Green: Measuring the Compensation Required to Site Electrical Generation Windmills in a Viewshed

A willingness to accept framework is used to measure the compensation required to allow wind generation windmills to be built in the mountains of North Carolina. We address why the NIMBY syndrome may arise when choosing site locations, the perceived property rights of view-sheds, as well as the perceptions of the status quo in the southern Appalachian Mountains. We find that individuals who perceive wind energy as a clean source of power require less compensation. Those who retire to the mountains or individuals who have ancestors from Watauga County require more compensation to accept windmills in their view-shed. We find that annual compensation is about twenty three dollars per household. In the aggregate, citizens need to be compensated by about one-half million dollars a year to allow wind electrical generation turbines in Watauga County. In addition, we find in a bivariate-probit analysis that individuals who are more likely to participate in a green energy program also are more likely to allow electrical generation wind mills in their view-shed suggesting that the green on green environmental debate is overstated.