Monetary economic valuation is relatively straightforward for ecosystem services and biodiversity aspects that are traded in markets or that can be related to markets, because market prices are available, which signal the scarcity of these environmental goods and can be used as a proxy for their value. A disadvantage of market-price and cost-based methods is that they focus on private costs and benefits associated with changes in ecosystems and neglect the costs and benefits of these changes to the public (Hansjürgens et al., 2012). For example, the water purification properties of forests are not only valuable to water supply companies that would benefit from avoided costs of using more complex water treatment methods, but also to the public that might value high water quality for recreational activities in adjacent streams or the existence of healthy aquatic life. Thus, in order to grasp the full extent of the values of ecosystems and their biodiversity additional methods, namely revealed and stated preference techniques, need to be applied. For purely public environmental goods that cannot be related to markets at all, stated preference methods (SP) are the only available means to assess their value (see Box 1, OECD, 2005).