How the valuation of environmental goods is related to income is a key question for economics, but the role of income inequality is often neglected. We study how income inequality affects the international transfer of the estimated value of environmental goods from a study to a policy site—a practice called value or benefit transfer. Specifically, we apply theory-driven, structural transfer factors to test whether adjusting for income inequality affects errors made in benefit transfer, drawing on a multi-country valuation study on water quality improvement. Our convergent validity analysis shows that the structural income inequality adjustment reduces benefit transfer errors by between 1.5 and 1.8 percentage points on average across all transfers. We therefore find that adjusting for income inequality offers only a minor improvement of benefit transfers as compared to adjusting for differences in mean income. Overall, our results shed light on the potential of structural approaches to benefit transfer for environmental valuation and public policy appraisal.

环境商品的价值与收入如何相关是经济学的一个关键问题，但是收入不平等的作用常常被忽略。我们研究收入不平等如何影响环境商品的估计价值从研究到政策场所的国际转移，这种做法称为价值或收益转移。具体而言，我们基于对水质改善的多国评估研究，运用理论驱动的结构转移因子来检验针对收入不平等的调整是否会影响收益转移中的错误。我们的收敛效度分析表明，结构性收入不平等调整将所有转移的收益转移误差平均降低了1.5至1.8个百分点。因此，我们发现，与调整平均收入差异相比，针对收入不平等进行调整只能带来较小的收益转移。总体而言，我们的结果揭示了采用结构性方法进行利益转移以进行环境评估和公共政策评估的潜力。