Trading in influence, or influence peddling, refers a person selling his/her influence over the decision making process to benefit a third party (person or institution). The difference with bribery is that this is a tri-lateral relation. From a legal point of view, the role of the third party (who is the target of the influence) does not really matter although he/she can be an accessory in some instances. It can be difficult to make a distinction between this form of corruption and some forms of extreme and loosely regulated lobbying where for instance law- or decision-makers can freely "sell" their vote, decision power or influence to those lobbyists who offer the highest compensation, including where for instance the latter act on behalf of powerful clients such as industrial groups who want to avoid the passing of specific environmental, social, or other regulations perceived as too stringent, etc. Where lobbying is (sufficiently) regulated, it becomes possible to provide for a distinctive criteria and to consider that trading in influence involves the use of "improper influence", as in article 12 of the Criminal Law Convention on Corruption (ETS 173) of the Council of Europe.
Try to answer this question if possible (otherwise reply "unanswerable"): Where lobbying is controlled, what does it provide for consideration to determine improper influencing?
distinctive criteria