This paper examines how the United States has valued harm to public resources in natural resource liability laws and practice, an early legal application of the ecosystem-services conceptual framework. Our primary focus is on valuing harm to the difficult-to-value resources and ecological services that provide indirect or passive human uses, for which revealed preference valuation methods (based on observable behavior) are not applicable. We concentrate on the past 25 years of U.S. experience with the innovative, restoration-based framework established in regulations implementing the Oil Pollution Act of 1990. By reframing the damage claims as the cost of both “primary” restoration (to promote recovery of injured resources) and “compensatory” restoration (to account for interim losses pending recovery), the regulations deflected some of the controversy surrounding valuation methods.

The restoration-based compensation framework provides two basic approaches for calculating the scale of compensatory restoration projects. A service-to-service approach, which does not require valuation, applies to projects that provide resources and ecosystem services of the same type, quality, and comparable value as those harmed. A valuation approach, intended for a broader range of applications, relies on survey-based methods.

For injuries to ecological services, we found trustees have relied almost exclusively on habitat equivalency analysis (HEA), a service-to-service approach, adapting its use to applications where restoration projects make resource and/or ecosystem services substitutions. We explore how the trustees address the challenge of characterizing the equivalency between injury and restoration resources and ecosystem services through the choice of restoration projects and the choice of the ecosystem service metrics. Widely used in the U.S. and EU, the restoration-based measure of damages and the associated HEA methodology may be useful for other countries.

本文研究了美国如何在自然资源责任法律和实践（生态系统服务概念框架的早期法律应用）中重视对公共资源的损害。我们的主要重点是评估对提供间接或被动人类用途的难以估价的资源和生态服务的危害，对于这些资源和生态服务而言，揭示的偏好评估方法（基于可观察到的行为）不适用。我们专注于过去的25 在基于1990年《石油污染法》的法规中建立的基于恢复的创新框架方面的多年美国经验。通过将损害索赔重新定义为“主要”恢复（以促进受伤资源的恢复）和“补偿性”恢复的成本（考虑到有待追回的中期损失），该法规转移了围绕估值方法的一些争议。

基于恢复的补偿框架提供了两种基本方法来计算补偿性恢复项目的规模。一个服务对服务的方法，该方法不需要估值，适用于提供资源和相同的类型，质量，和那些损害价值相当的生态系统服务的项目。用于更广泛应用的评估方法依赖于基于调查的方法。

对于生态服务的损害，我们发现受托人几乎完全依赖栖息地当量分析（HEA），这是一种服务到服务的方法，使它的使用适应于恢复项目替代资源和/或生态系统服务的应用。我们探索受托人如何通过选择恢复项目和选择生态系统服务指标来应对表征伤害与恢复资源和生态系统服务之间的等效性的挑战。基于恢复的损害赔偿措施和相关的HEA方法在美国和欧盟中广泛使用，可能对其他国家/地区有用。