163Moreover, it is not necessary for the economic analysis of the costs and benefits to be made on the basis of a precise calculation of the respective costs of the action proposed or of inaction. Such precise calculations will in most cases be impossible to make, given that, in the context of the application of the precautionary principle, their results depend on different variables which are, by definition, unknown. If all the consequences of inaction and of action were known, it would not be necessary to resort to the precautionary principle; it would be possible to decide on the basis of certainties. In conclusion, the requirements of the Communication on the precautionary principle are satisfied where the authority concerned — in the present case, the Commission — has in fact acquainted itself with the effects, positive and negative, economic and otherwise, to which the proposed action, as well as the failure to act, may lead, and has taken that into account in its decision. By contrast, it is not necessary for those effects to be estimated precisely, if that is not possible or would require disproportionate effort.