The total economic value of threatened, endangered and rare species: An updated meta-analysis

This paper updates a 1996 meta-analysis of studies using the Contingent Valuation Method (CVM) to value threatened, endangered and rare species published in this journal by Loomis and White. A variable for studies conducted in or after 1995 was added to the model to test if new studies are systematically different from old studies and identify which explanatory variables influencing willingness-to-pay (WTP) for these species have changed over time. Generally newer studies yielded higher WTP. Variables such as the change in the size of the species population, payment frequency, survey mode, response rate, type of respondent, type of species, and a new variable for whether a species is a ‘charismatic megafauna’ or not, whether the species has use and nonuse value versus nonuse value only and year of the study, were found to significantly influence WTP. This model is used in a benefit transfer example and a comparison of original study estimates and model estimates is made to compare its accuracy. The average within sample benefit transfer error was 34-45%.