Such social costs have two characteristics, which seem distinct but are indeed the two sides of the same coin, once looked at from a structural or methodological point of view and once looked at from a policy-making perspective. Social costs arise where issues are too complex, too new or too indefinite in nature in order to be given a monetary value that would allow for market transactions. Economics has coined the notion of “transaction costs”, which include the costs of generating, codifying and transmitting information, as a catch-all term for all the factors that are preventing decision making on the optimal level of a good, say the level of security of supply, by way of the price mechanism determined by the forces of supply and demand. In other words, without alternative forms of intervention, e.g. political decisions or the legal system, such external impacts will not be taken into account by producers and consumers with the result that positive externalities will be undersupplied and negative externalities oversupplied (see Section 1.3 for more details).