As the underlying premise of techniques in this category, damage to natural resources and the services they provide can be measured in monetary terms and compensated through provision of physical resources and services (Lipton et al., 2018[4]). Under the value-to-cost version, the monetary assessment of the damage ensuing from the incident is set as the budget for remediation, the benefits of which are not estimated directly (European Commission, 2013[2]). Under the value-to-value version, both the value of damage and the benefits from remediation are measured in monetary terms (European Commission, 2013[2]). Although compensation may be measured (or scaled) in monetary terms, compensation under the ELD can only be provided in resource-based units, not money (Chapman, Scott and Özdemiroğlu, 2018[7]). This is where the ELD and other frameworks of environmental liability differ from the “indirect” method of assessment in Kazakhstan.
In value equivalency, monetary values are based on individuals’ preferences for given changes in the quality and/or quantity of resources of service (Chapman, Scott and Özdemiroğlu, 2018[7]). There are two means of measuring preference: i) individuals’ willingness to pay money (WTP) to avoid an environmental loss or to secure a gain; or ii) their willingness to accept money as compensation (WTAC) to tolerate an environmental loss or to forgo a gain (Chapman, Scott and Özdemiroğlu, 2018[7]). Environmental values that depend upon people’s actual use of the environment are referred to as use values. Those that derive from people’s contentment from knowing that environmental resources are preserved even if they do not directly use or interact with them, or never will, are referred to as non-use or existence values (Hanley, 2002[8]). Reductions and gains in use and non-use values will be included in the debit and credit estimates in equivalency analysis conducted in relation to environmental damage arising under the ELD (Chapman, Scott and Özdemiroğlu, 2018[7]). As these types of values are often not priced in the market, two broad techniques have emerged that help determine appropriate monetary values for the equivalency analysis: