Table 2. Nonexhaustive list of institutional contexts under which PES may be implemented. Characteristics on the left side of the options are generally (although not always) easier contexts for implementing PES. These choices often rest within a continuum rather than a dichotomy. Characteristics Institutional context Options Service provider governance type democratic vs. authoritarian   type of provider individual vs. community   property tenure private property vs. no tenure   legality of behaviors legal vs. illegal   opportunity costs homogenous vs. variable           Buyer buyer’s funding secure vs. insecure   buyer goals to trade-off economic efficiency vs. equitable distribution   additional buyer goals to trade-off social vs. ecological           Relationship threats to system internal vs. external   distance between buyer and provider local vs. international   relationship between buyer and provider one-on-one vs. intermediaries   negotiations market-based vs. one-off/project-based negotiation   participation constraints voluntary vs. regulated