How reliable are meta-analyses for international benefit transfers?

Meta-analysis has increasingly been used to synthesise the environmental valuation literature, but only a few test the use of these analyses for benefit transfer. These are typically based on national studies only. However, meta-analyses of valuation studies across countries are a potentially powerful tool for benefit transfer, especially for environmental goods where the domestic literature is scarce. We test the reliability of such international meta-analytic transfers, and find that even under conditions of homogeneity in valuation methods, cultural and institutional conditions across countries, and a meta-analysis with large explanatory power, the transfer errors could still be large. Further, international meta-analytic transfers do not on average perform better than simple value transfers averaging over domestic studies. Thus, we question whether the use of meta-analysis for practical benefit transfer achieves reliability gains justifying the increased effort. However, more meta-analytic benefit transfer tests should be performed for other environmental goods and other countries before discarding international meta-analysis as a tool for benefit transfer.