Date of Graduation

2015

Document Type

Dissertation

Degree Type

PhD

College

Davis College of Agriculture, Natural Resources and Design

Department

Forest Resource Management

Committee Chair

Kathryn A Gazal

Committee Co-Chair

James T Anderson

Committee Member

Alan R Collins

Committee Member

James S Rentch

Committee Member

Jingxin Wang

Abstract

This research paper provides a benefit transfer model of willingness-to-pay (WTP) for wetlands' biodiversity conservation in the United States. The validity of the estimated wetland's willingness-to-pay values is also examined. While valuation of the services provided by wetlands may be challenging due to their non-market nature, estimation of values is important. Conducting a primary study is the best option for precise results. However, researchers may recommend the benefit transfer approach in wetland valuation when there are limited time, budgetary constraints, and administrative urgency.;The benefit transfer approach involves transferring of value estimates from study sites (where research was already undertaken) to policy sites (where values are to be applied). This study extends and provides improvements to wetlands valuation literature by using information obtained from 21 study sites---19 natural wetlands and 2 constructed or human made wetlands to estimate the values of wetlands for biodiversity conservation on six policy sites---5 natural wetlands and 1 constructed wetland. Suitable meta-regression models have been developed to explain the values of biodiversity service provided by natural and constructed wetlands in the contiguous United States.;Meta-regression results are reported for eight models out of which models 7 and 8 are analyzed and compared for validity. In doing so, forty out of forty two observations in model 7 and thirty nine out of forty one observations in model 8 have underestimated WTP values as compared to the author reported WTP values at the study sites. The WTP values for policy sites ranged from {dollar}0.82 (Henderson Slough) to {dollar}29.69 (human-made wetland) in model 7 and from {dollar}1.63 (Henderson Slough) to {dollar}66.47 (Mobile Delta/Fahkatchee) in model 8. Policy site WTP values were adjusted with average transfer errors. Adjusted WTP is being done in response to the failure of validity test #4 and the predominance of WTP underestimation on the study sites. The adjusted WTP ranged from {dollar}4.02 (Henderson Slough) to {dollar}145.04 (human-made wetland) in model 7 and from {dollar}12.17 (Henderson Slough) to {dollar}496.07 (Mobile Delta/Fahkatchee) in model 8.;The results of validity test #1 shows an average transfer error that is lower in model 7 (average TE=79.53%) compared to model 8 (average TE=86.60%), which indicates that model 7 is slightly better. Validity test # 2 indicates that the difference between the original and estimated WTP is not different from zero in both models (p=0.243 for 7 and p=0.242 for 8). Therefore, WTP estimates obtained from these models are acceptable. The validity test of functional relationship (validity test # 3) between the original and estimated WTP in model 7 (F2,39=1.624) and model 8 (F2,38 =1.243) indicates that WTP amounts converge to each other. Therefore, this test shows that WTP estimates are acceptable for both models. Correlation (validity test # 4) between original and estimated WTP in model 7 (0.00) and model 8 (0.14) indicates that the WTP amounts are not correlated or they have weak relationship, which rejects the validity for both models.

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