Table 2

Systematic Standardization Protocol Example

Order of StepsValueIndicatorSourceNote
Extract original value€0.15 per household per monthOriginal WTP for NBSViti et al. (2023)Aarhus, Denmark
Obtain data from region336,000PopulationAarhus city hall dataaOfficial population (2022)
173,000HouseholdsAdminStatbNo. of households (2021; latest)
68,299GDP per capitaWorld Bank datacGDP per capita (2022 US$)
Adjust to 2022 pricesNo operation neededGDP deflators
Exchange to US$ and correct for PPP6.153561PPP exchange rate (Danish kr. to US$)World Bank dataPPP conversion factor, GDP (LCU per international US$) (2022)
7.43US$ to Danish kr. exchange rateEuropean Central BankdEuro Foreign Exchange Reference Rates (2022)
1.11WTP (Danish kr.)WTP × exchange rate
0.18Monthly value (2022 US$)Kr. WTP / PPP exchange rate
Obtain final per hectare per year WTP value2.17Annual value (2022 US$)Monthly WTP × 12
375,994Aggregated valueYearly WTP × HH
2,426WTP per hectare per year (2022 US$)Aggregated WTP / size (ha)