Paradigm CES Paradigm COS Paradigm CIS Examples in global literature Most of the Voluntary Carbon Market Proambiante program, Brazil Pimampiro, Ecuador PSA program, Costa Rica Most of the payment schemes for (assumed) watershed functions in Latin America and Asia Grain for Green project, China National PES project, Vietnam Andes, Bolivia (Asquith et al. 2008) Example studies in RUPES (Table 1) Sumberjaya (River Care) Singkarak (Voluntary Carbon Market) Kalahan (Voluntary Carbon Market) Cidanau Bungo Singkarak (Watershed) Sumberjaya (Community Forestry) Bakun Kulekhani Do schemes meet the principles? Realistic Yes, as long as ES is measurable Only if correctly targeted; mostly long-term Mostly long-term Voluntary Yes, for those who are in a position to control and enhance ES Yes, for those with rights and opportunity to reduce ES Yes, for collective action scheme, FPIC depending on local social capital and decisions Conditionality (Fig. 1) Level I Levels II–III Levels I–IV Pro-poor Possibly not, presupposes tenure security Possibly yes, depending on allocation rules Mostly yes, depending on local institutions Primary strength The output is based on the ES provision, ensuring the effect of the project Relatively easy to monitor with tangible indicators at effort level rather than outcome level Trust-building and reciprocity redress past inequalities Primary challenge Considerable risk to the ES providers if their efforts do not pay off. The monitoring process requires technical capacity because of complexity in measuring ES. The conditionality might not directly link with the ES provision. Buyers have budget restriction for the financial payments. Need high trust between the seller and buyer. Similar to COS, the conditionality might not directly link with ES provision and financial opportunity cost might not be fully paid.