Apparatus for inserting and removing specimens from high temperature vacuum furnaces

The apparatus comprises a high speed gate valve for isolating the interior of the furnance from an air lock chamber on the opposite side of the gate valve. The air lock chamber is provided with valve ports connected to a vacuum source, a source of inert quenching gas, and the atmosphere, respectively. Attached to the end of the air lock chamber away from the furnace is a cylindrical tube having disposed within it a rod carrying specimen pan at the end towards the furnace and having mounted at its top end an annular magnet having a diameter slightly less than the interior diameter of the tube. The top end of the tube is closed by a removeable cap. Encircling the tube in the vicinity of the magnet is a carbon steel ring which when axially moved along the tube causes the magnet to follow it and thereby controls the position of the rod and specimen pan within the tube

MEASURING USE VALUE FROM RECREATION PARTICIPATION

Recreation demand studies have traditionally utilized a two-step valuation method, estimating condtional recreation participation probabilities and then intensity of use decisions. These two steps of analysis are combined to estimate the use value of natural resource recreation sites. The purpose of this paper is to provide a method by which use value can be estimated solely from the participation decision. The one-step resource valuation method allows estimation of use values from coefficients of the logistic regression recreation participation equation. The benefits of the method are the reduced data and effort required to value natural resource areas.Resource /Energy Economics and Policy,

MEASURING USE VALUE FROM RECREATION PARTICIPATION: REPLY

Resource /Energy Economics and Policy,

Total Economic Values for Coastal and Marine Wildlife: Specification, Validity and Valuation Issues

Benefit-cost analysis of coastal and marine wildlife management programs requires that economic benefits be monetized for comparison with the costs of preservation. Without explicit measurement and consideration of nonuse values, benefits may be underestimated and resources devoted to wildlife programs may be underallocated. Using data from a contingent valuation survey of nongame wildlife programs in coastal North Carolina, this paper provides additional evidence that total economic values under uncertainty for wildlife are theoretically valid. Specification error is found for valuation models which do not include measures of uncertainty. Specification error can lead to errors in benefit estimation.contingent valuation, option price, specification, validity, Environmental Economics and Policy, Research Methods/ Statistical Methods,

Contingent Valuation and Random Utility Model Estimates of the Recreational Value of King Mackerel

This paper estimates the value of king mackerel bag limit changes with both stated and revealed preference methods. The 1997 Marine Recreational Fishery Statistical Survey allows estimation of the value of avoiding bag limit reductions with the random utility model and the contingent valuation method. Using the contingent valuation method, the willingness to pay to avoid a one fish reduction in the bag limit is $2.45 per year. Using the random utility model, the willingness to pay to avoid a one fish reduction in the bag limit for a two-month time period is$10.83. Considering several methodological issues, the difference in willingness to pay between the stated and revealed preference methods is in the expected direction.

Improving Willingness to Pay Estimates for Quality Improvements through Joint Estimation with Quality Perceptions

Willingness to pay for quality change may depend on heterogeneous perceived quality levels. In these instances, contingent valuation studies should include measures of quality perceptions as covariates in the willingness to pay model in order to avoid omitted variable bias. Variation in quality perceptions across respondents leads to a potential endogeneity of quality perceptions. We address the potential for endogeneity bias using an instrumental variables approach in which a measure of quality perceptions is included as a determinant of willingness to pay and is simultaneously determined by various exogenous factors. The willingness to pay model is estimated jointly with quality perceptions allowing for correlation of the error terms. Using data on willingness to pay for water quality improvements in the Neuse River in North Carolina we reject exogeneity of perceived quality. Correcting for endogeneity improves the measurement of willingness to pay by differentiating willingness to pay among respondents with heterogeneous quality perceptions.

Environmental Risk and Averting Behavior: Predictive Validity of Revealed and Stated Preference Data

We conduct predictive validity tests using revealed and stated behavior data from a panel survey of North Carolina coastal households. The application is to hurricane evacuation behavior. Data was initially collected after Hurricane Bonnie led to hurricane evacuations in North Carolina in 1998. Respondents were asked for their behavioral intentions if a hurricane threatened the North Carolina coast during the 1999 hurricane season. Following Hurricanes Dennis and Floyd in 1999, a follow-up survey was conducted to see if respondents behaved as they intended. A jointly estimated revealed and stated behavior model indicates that the hypothetical and real evacuation behavior is based on the same choice process. Using predictions from this model with a hypothetical bias correction we find that it predicts actual evacuation behavior with small forecast error. These results suggest that stated behavior data has some degree of predictive validity.

SOUTHEAST MARINE RECREATIONAL FISHERY STATISTICAL SURVEY: DISTANCE AND CATCH BASED CHOICE SETS

In this paper we estimate the economic value associated with marine recreational fishing in the southeast United States using the random utility model. The data used is the Southeast (North Carolina to Louisiana) Marine Recreational Fishery Statistics Survey (SE MRFSS). The geographic extent of the market and potential catch are used to determine the effect of choice set definition on random utility model parameter and welfare estimates. We find that choice sets based on distance or catch do not lead to large differences in the compensating variation of a fishing trip. Defining choice sets based on catch does lead to insignificant estimates of the effect of one measure of site quality on site selection. We also find differences in the value of an additional fish when comparing alternative measures of site quality.Resource /Energy Economics and Policy,

Temporal Reliability of Willingness to Pay from the National Survey of Fishing, Hunting, and Wildlife-Associated Recreation

The U.S. Fish and Wildlife Service's National Survey of Fishing, Hunting, and Wildlife Associated Recreation has been a source of information on wildlife-related recreation since 1955. The contingent valuation method has been used to estimate willingness to pay for recreation trips in the 1980, 1985, 1991, 1996 and 2001 surveys. However, relatively little comparative analysis over time has been performed. Similar value elicitation formats were used in the 1991 and 1996 surveys for bass and trout fishing, deer hunting, and nonconsumptive wildlife recreation. We statistically analyze these data to assess the temporal reliability of the willingness to pay. We control for the effects of trip quality and socioeconomic variables and find that willingness to pay is significantly lower in 1996 for each activity. A subtle, but important, change in the 1996 question format may drive the result of lower willingness to pay.

Estimating Environmental Benefits of Natural Hazard Mitigation with Benefit Transfer: Results from a Benefit-Cost Analysis of FEMA Hazard Mitigation Grants

This paper summarizes methods, data, and results associated with the first major attempt to evaluate the environmental benefits of FEMA natural hazards mitigation grants. The study relied heavily on the refinement of benefit transfer methods. Categories of benefits include water quality for recreational and commercial fishing, drinking water, outdoor recreation, hazardous waste, wetlands and aesthetic, health and safety benefits. Environmental and historic benefits proved to be a very minor proportion of the total benefits in dollar terms. Only a very small percentage of earthquake and wind-related hazards yielded environmental benefits, while a sizeable percentage of flood hazard grants did so. We also discuss the prospects that environmental benefits might have been much greater had data been available to analyze more environmental impacts. Key Words: Natural Hazard Mitigation, Environmental Benefits