With the rising popularity of the ecosystem service (ES) concept the interplay of stakeholders in a world shaped by increasingly globalised markets, government regulations in land use and markets as well as technological progress, e.g. in agriculture is gaining attention. Arguably, we do not lose biodiversity primarily for lack of understanding the drivers of ecosystem degradation or adequate conservation funding. Barriers to biodiversity conservation also arise from poor policy design and conflicting interests of land users due to neglected adverse (sometimes perverse) economic incentives, as well as a lack of monitoring and enforcement. Against this background, ecosystem service governance can be defined as the shaping and institutionalisation of mechanisms for mutual decision-making by involved actors for the management of ecosystems for biodiversity conservation and ecosystem service provisioning (Rival and Muradian, 2013). According to Primmer and Furman (2012) the governance of ecosystem services merges knowledge from different disciplines and integrates stakeholders who understand, manage and benefit from ecosystem services.
A major challenge in ecosystem service governance is the multiplicity of actors involved (Loft et al., 2015). As the manifold approaches to assess the value of nature have shown, nature is a multifaceted source of well-being to humankind and degradation of ecosystems lead to tremendous costs to national economies (see exemplarily Pascual et al., 2017, Costanza et al., 2014). However, stakeholders in ecosystem service governance are not only numerous. They are also diverse and relate to the framework of ecosystem services quite differently (Ruckelshaus et al., 2015). Their interests in how ecosystems are managed differ depending on whether they demand or supply ecosystem services (Rode et al., 2016). As beneficiaries and providers are typically dispersed vertically at multiple governance levels and horizontally across sectors there is often a lack of coordination among them (cf. Plieninger et al., 2012, Wüstemann et al., 2017). Stakeholders typically hold multiple values for ecosystem services and moreover individual value judgments often lack transparency and a shared understanding about what is perceived as a service and what are appropriate value articulating institutions to express the importance of a service (cf. Vatn, 2005, Martín-López et al., 2014, Díaz et al., 2015, Maier and Feest, 2016). Furthermore, property rights are often poorly defined among stakeholders and may hamper the acceptance and effectiveness of management options as well as policy responses (cf. Mascia and Claus, 2009, Lockie, 2013). Also power relationships influence the access of individuals or groups to ecosystem services benefits (Felipe-Lucia et al., 2015).
Despite these difficulties, there is a broad recognition that non-marketed ecosystem services have been undervalued in decision-making, thus causing biodiversity loss and ecosystem degradation (see e.g. TEEB, 2010). High hopes are placed on economic valuation of ecosystem services to facilitate a mutual understanding about trade-offs in ecosystem service provision and to identify potential solutions for ecosystem service management (Sukhdev, 2009, Ring et al., 2010). Economic valuation can make explicit that biodiversity and ecosystem services are scarce and that their decline generates costs to society (Pascual et al., 2010). Economic value encompasses a range of different value categories ranging from direct over indirect use values to non-use values (Johnston et al., 2017). All these value categories are represented in the Total Economic Value (TEV) framework depicted in Fig. 1. While some benefits can be valued with methods that make use of market prices (e.g. crops, recreation), benefits that cannot be related to markets (e.g. bequest or existence values) need to be valued through stated preference (SP) methods. SP are elicited in surveys that ask respondents to state their preferences for a change in the state of an ecosystem in the form of their willingness to pay (WTP) to obtain an environmental improvement or to avoid an environmental deterioration, or willingness to accept (WTA) compensation for abandoning an environmental deterioration or to forgo an environmental improvement. SP methods include Contingent Valuation (CV) and Choice Experiments (CE) (see description in Box 1).
Using monetary values for changes in biodiversity and ecosystem service provision offers a common unit and welfare measure and may thus help to put ecosystem services on par with other (economic) interests in ecosystem service management. Ultimately, this may facilitate mainstreaming the importance of natural capital in decision-making outside the environmental sector (Hansjürgens et al., 2016). Economic valuation, however, is also a much contested way of relating to nature. There are a considerable number of critical reflections on the use of economic valuation to promote nature conservation, both from within science as well as from societal groups. With respect to the above mentioned ecosystem service governance challenge two main strands of literature deem particular attention. On the one hand, there are doubts that economic valuation methods the manifold value dimensions inherent to nature (O'Neill and Spash, 2000, Vatn, 2009, Chan et al., 2012). On the other hand, it is questioned whether and how economic valuation can inform political decision-making (cf. Laurans et al., 2013).
In this paper, we will build upon these discussions and explore the importance of SP methods in tackling a major challenge of ecosystem service governance: the involvement of multiple actors and their heterogeneous perception and appropriation of ecosystem services. By referring to specific valuation exercises for different purposes (project and policy appraisal, policy instrument design, and awareness raising) we highlight four contributions of SP studies (stimulating societal debate, inclusion of non-market ecosystem services in CBA, consideration of distributive effects of ecosystem service management, gaining behavioural insights) in Section 2. In Section 3 we reflect on the methodological weaknesses of SP methods and discuss the potential of deliberative valuation for addressing these limitations. Section 4 provides concluding remarks.Characteristics of two main preference-based valuation methods
Contingent valuation (CV) is a survey-based method that elicits people’s preferences directly by using one of the following measures: willingness to pay (WTP) to obtain an environmental improvement or to avoid an environmental deterioration, or willingness to accept (WTA) compensation for relinquishing an environmental deterioration or to forgo an environmental improvement. The method bypasses the need of a market for environmental assets by presenting individuals with a hypothetical market in which they have the opportunity to buy (WTP) or sell (WTA) the environmental good in question. People’s actions are contingent on the hypothetical situation described to them, and elicited WTP and WTA bids are close to the value that would be revealed if an actual market existed.
CV surveys contain of three parts: Firstly, a detailed description of the environmental asset or change being valued and the hypothetical market. Secondly, questions that elicit respondents’ WTP and/or WTA amounts. Thirdly, questions about respondents’ socio-economic characteristics and their attitudes towards the environment for validity testing. Once WTP/WTA bids have been obtained, the total value estimate of the environmental good or change is derived by the calculation of mean WTP/WTA and its aggregation to the total population. The last stage of a CV study involves a validity assessment of WTP/WTA estimates.
Choice Experiments are similar to CV with the main difference that respondents do not express their WTP or WTA for a certain environmental change directly. Instead, they are presented with alternative policy options from which they have to choose the one they prefer most. The policy options have shared attributes of the environmental goods at stake, but with different attribute levels. One of the attributes is the cost that respondents would have to pay for an enhancement in the state of the ecosystem in question or the compensation people would receive for the deterioration from that state.
