Benefit Transfer (BT) is often applied when a primary valuation study is considered too costly or time consuming to conduct. It is commonly assumed that BT performance improves with increasing similarity between study and policy sites. However, no common criteria for defining similarity exist, making it difficult to operationalise the concept of similarity in a practical BT context. We propose a structured framework for distinguishing between different degrees of similarity. In particular, we differentiate between three dimensions: physical, population and attribute similarity. While the first two are often used in the literature, attribute similarity is not. To investigate the impact attribute descriptions have on BT, we define it as whether or not the same ecosystem service categories are emphasised in the valuation studies. Using value estimates for water quality improvements obtained from 17 Choice Experiments conducted in Europe, we empirically test unit value transfer performance along a similarity gradient. The results confirm that increasing physical similarities across commodities and sites generally lead to lower transfer errors. However, when using income adjusted value transfer, we surprisingly find the opposite. Finally, we demonstrate that increasing attribute similarity may offset dissimilarities in terms of the site characteristics.

当初级评估研究被认为过于昂贵或耗时时，通常会应用利益转移（BT）。通常认为，随着研究站点和政策站点之间的相似度增加，英国电信的绩效也会提高。但是，不存在用于定义相似性的通用标准，这使得在实际的BT环境中难以操作相似性的概念。我们提出了一个结构化的框架，用于区分不同程度的相似性。特别是，我们在三个维度之间进行区分：物理，人口和属性相似度。尽管在文献中经常使用前两个，但属性相似性却不是。为了调查描述对BT的影响属性，我们将其定义为在评估研究中是否强调相同的生态系统服务类别。使用从欧洲进行的17个“选择实验”获得的水质改善价值估算值，我们以相似梯度对经验值进行了性能测试。结果证实，商品和地点之间物理相似度的提高通常会导致转移误差降低。但是，当使用收入调整后的价值转移时，我们惊讶地发现了相反的情况。最后，我们证明了增加的属性相似性可以抵消站点特征方面的相异性。当使用收入调整后的价值转移时，我们惊讶地发现了相反的情况。最后，我们证明了增加的属性相似性可以抵消就站点特征而言的相似性。当使用收入调整后的价值转移时，我们惊讶地发现了相反的情况。最后，我们证明了增加的属性相似性可以抵消站点特征方面的相异性。