PlutocracyGreek ploutos meaning wealth).
The term plutocracy is generally used to describe two unrelated phenomena. In writings about history, plutocracy is the political control of the state by an oligarchy of the wealthy. Examples of such plutocracy include some city-states in Ancient Greece and the Italian merchant republics of Venice, Florence, and Genoa.
Plutocracies typically emerge as one of the first governing systems within a territory after a period of anarchy. Plutocracy is closely related to aristocracy as a form of government, as generally wealth and high social status have been closely associated throughout history.
The second usage is a pejorative reference to the allegedly great and undue influence the wealthy have on the political process in contemporary society. This influence can be exerted positively (by financial "contributions" or in some cases, bribes) or negatively by refusing to financially support the government (refusing to pay taxes, threatening to move profitable industries elsewhere, etc).
Recently, there have been numerous cases of wealthy individuals exerting financial pressure on governments to pass favorable legislation. Most western partisan democracies permit the raising of funds by the partisan organisations, and it is well-known that political parties frequently accept significant donations from various individuals (either directly or through corporate institutions). Ostensibly this should have no effect on the legislative decisions of elected representatives; however it would be unlikely that no politicians are influenced by these "contributions". The more cynical might describe these donations as "bribes", although legally they are not. In the United States, campaign finance reform efforts seek to ameliorate this situation.