Economic cost

Sacrifice associated to the use of available resources to one means instead of another (so that any economic cost is indeed an opportunity cost) or of following one course of action instead of the best available alternative. As applied to NWRM, it refers to those negative impacts in terms of welfare, either direct or indirect, that may be linked to the implementation of any measure.
The difference between explicit and implicit costs depends on whether there is an unequivocal monetary payment (or at least one which is straightforward to infer) or not. The term ﾓdirect (economic) costﾔ does actually refer to those costs that fall directly on the promoter of the NWRM. Hence, as opposed to direct costs, indirect costs are those incurred by others (those who are not under the direct scope of the NWRM implementation).