The Empirics of Wetland Valuation: A Comprehensive Summary and a Meta-Analysis of the Literature

Abstract

Wetlands are highly productive ecosystems, providing a number of functions (products and services) that are of value to people. The open-access nature and the public-good characteristics of wetlands often result in wetlands being undervalued in decisions relating to their use and conservation. There is now a substantial literature on wetland valuation, including two meta-analyses. These meta-analyses examine subsets of the available wetland valuation literature, focusing on temperate wetlands, a limited set of wetland functions, and a limited set of valuation techniques. We collect over 190 wetland valuation studies, providing 215 value observations, in order to present a more comprehensive meta-analysis of the valuation literature that includes tropical wetlands (e.g., mangroves), estimates from diverse valuation methodologies, and a broader range of wetland functions (e.g., biodiversity value).We also aim for a more comprehensive geographical coverage. We find that socioeconomic variables, such as income and population density, that are often omitted from such analyses are important in explaining wetland value. We also assess the prospects for using this analysis for out of sample value transfer, and find average transfer errors of 74%, with just under one-fifth of the transfers showing errors of 10% or less. This overall performance is, however, dominated to a considerable extent by transfer to small sites. The performance of value transfer for medium to large wetlands on average shows transfer errors smaller than 30%.

Exploring spatiotemporal changes in ecosystem-service values and hotspots in China

“…Thus, VC k is an extremely important parameter in this model. Fundamental information on the VC k was sourced from a number of databases, including the COPI Valuation database (Braat et al, 2008 andENVAlue, 2004), ESD-ARIES (UVM, 2008), ValueBaseSwe (Sundberg and Söderqvist, 2004), and EcoValue (Wilson et al, 2004), along with other relevant studies with data on ecosystem-service values (e.g., Costanza et al, 1997;De Groot et al, 2002;Brander et al, 2006). Strict criteria were followed for data selection.…”

The Values of Natural and Constructed Wetlands: A Meta-Analysis

“…The dataset developed by (Brander et al 2006) provided the starting point for the analysis. The original dataset -consisting of 215 value observations from 80 studies -was substantially enlarged with new observations from recently published studies.…”

“…The base meta-analytical regression model is specified as follows: (Brander et al 2006). Values referring to different years were deflated using appropriate factors from the World Bank Millennium Development Indicators (World Bank Group 2006), while differences in purchase power among the countries were accounted for by the PPP index provided by the Penn World Table (Heston et al 2006).…”

“…Also, to distinguish between marginal and average per hectare values, a dummy variable that equals one for marginal values is introduced (Brander et al 2006). …”

“…Three previous meta-analyses of wetland values (Brander et al 2006;Brouwer et al 1999; investigation.…”