Biodiversity metrics and biodiversity values for the public appraisal of biodiversity: synthesising and extending the evidence.

世界正面临着生物多样性危机。尽管生物多样性具有价值，但在经济决策中却被系统性地忽视了。这项提案将通过综合迄今在评估生物多样性方面的经验教训来解决这一缺陷，并确定如何将这些价值纳入决策的主流，以积极影响生物多样性政策和成果。正如许多出版物所强调的那样，生物多样性通过多种生态系统服务(例如授粉、气候调节、防洪)为人们的福祉做出贡献。几十年的研究使我们能够准确地估计土地使用决策与生物多样性结果和生态系统服务价值之间的关系。然而，人们也仅仅从知道生物多样性存在(“存在价值”)中获得幸福。这项研究将探索将这些价值纳入经济决策的两种方法：1)通过衡量人们对生物多样性的支付意愿(WTP)；2)通过实现商定的生物多样性政策目标(例如净收益)的成本：基于成本的方法。该提案将首先对WTP方法进行批判性审查和综合。如果存在对WTP的一致估计，这是经济学家首选的方法--因为它允许通过权衡收益与成本，在生物多样性成果和其他商品(例如，卫生、教育)之间优化资源分配。然而，WTP估计中有众所周知的不一致之处(例如WTP对生物多样性供应的增加没有反应，对框架很敏感)，这是因为人们难以解释生物多样性与金钱的权衡。因此，我们将审查另一种评估程序--基于成本的方法--如何实施。在英国，25年环境计划的目标是“自然积极”或生物多样性净收益。这可以作为基于成本的方法的目标。虽然目标是明确的，但净收益的雄心并没有说明应该使用哪种生物多样性衡量标准来衡量是否实现了净收益。这是有问题的，因为生物多样性是多方面的，人们的福祉受到不同方面的不同影响。以成本为基础的方法以反映公众偏好(公众想要什么与生物多样性有关)的生物多样性指标为导向，需要确定生物多样性的不同方面如何影响幸福感，以及这些因素如何与不同的生物多样性指标相一致。为了实现这一目标，我们将综合不同的生物多样性指标。我们将把这一点与一个专门设计来梳理生物多样性指标和人们偏好之间关系的经济实验结合起来，并用一个有代表性的样本进行这个实验，以提供人们重视生物多样性哪些方面的经验证据，同时避免要求他们进行困难和有争议的生物多样性金钱权衡。一旦建立了评估实现净收益的适当指标，该提案将通过NEV建模套件确定满足目标的成本。这意味着生物多样性的货币价值随后将用于政策评估和指导决策，使其远离对生物多样性的有害影响。最后，研究将使用NEV模型来演示土地利用、福利和生物多样性，以及不同政策方法的影响。考虑到HMT的《达斯古普塔生物多样性经济学评论》的建议，这项研究议程非常及时。它将对其他以指标为导向的方法产生明显的影响(例如，金融部门的披露和住房开发项目的净收益要求)。此外，这项研究将作为如何评估生物多样性的价值并将其应用于政策评估的原则证明，鉴于这项研究希望影响的英国政府公共投资评估指南的声誉，这将在全球范围内使用。

The world is facing a biodiversity crisis. Despite biodiversity's value, it is systematically ignored in economic decision making. This proposal will address this shortcoming by synthesising the lessons to date in valuing biodiversity, and establishing how these values can be mainstreamed in decision-making to positively affect biodiversity policy and outcomes. As numerous publications highlight, biodiversity contributes to people's wellbeing through multiple ecosystem services (e.g. pollination, climate regulation, flood prevention). Decades of research allows us to accurately estimate the relationship between land-use decisions and both biodiversity outcomes and ecosystem service values. Yet, people also derive well-being from simply knowing that biodiversity is there ("existence value"). This study will explore the two methods for incorporating these values within economic decision making: 1) via measuring people's Willingness-To-Pay (WTP) for biodiversity; 2) via the cost of meeting an agreed policy target (e.g. net-gain) for biodiversity: a cost-based approach.The proposal will first critically review and synthesise the WTP approach. If consistent estimates of WTP exist, it is the economist's preferred approach - as it allows for the optimal allocation of resources across biodiversity outcomes and other goods (e.g. health, education) by weighing benefits against costs. However, there are well known inconsistencies in WTP estimates (e.g. WTP is unresponsive to increases in biodiversity provision, and is sensitive to framing), which arise because people struggle to interpret biodiversity-money trade-offs. We will therefore review how an alternative valuation procedure - the cost-based approach - could be operationalised.In the UK the target in the 25-year Environment Plan is "nature-positive" or biodiversity net-gain. This can be used as the target for a cost-based approach. While the aim is clearly articulated, the net-gain ambition does not state which metric of biodiversity should be used to measure whether net-gain is achieved. This is problematic given biodiversity is multifaceted, and people's well-being is differently affected by different aspects. Orienting the cost-based approach around a biodiversity metric that reflects public preferences (what the public want in relation to biodiversity) requires establishing how well-being is affected by different aspects of biodiversity and how these tally with different metrics of biodiversity.To achieve this aim, we shall synthesise the different metrics of biodiversity. We will couple this with an economic experiment specifically designed to tease apart the relationships between biodiversity metrics and people's preferences, and conduct this experiment with a representative sample to provide empirical evidence of which aspects of biodiversity people value, while avoiding asking them to perform difficult and controversial biodiversity-money trade-offs. Once an appropriate metric is established to assess achieving net-gain, the proposal will determine the cost meeting the target though the NEV modelling suite. This implied monetary value of biodiversity would then be used in policy appraisal and guide decisions away from harmful biodiversity impacts. Finally, the research will use the NEV modelling to demonstrate the land-use, welfare and biodiversity, implications of different policy approaches. The research agenda is extremely timely given the recommendations of HMT's Dasgupta Review on the Economics of Biodiversity. It will have obvious ramifications for other metric-driven approaches (e.g. disclosure in the financial sector and the net-gain requirement for housing developments). Moreover, the research will act as a proof-of-principle for how biodiversity's value can be estimated and applied in policy appraisal, which will be of use globally given the reputation of the UK government guidelines on public investment appraisal that this research hopes to influence.