Medium of exchange was observed as early as Oresme, Copernicus and then in 1558 by Sir Thomas Gresham, that bad money drives out good in any marketplace (Gresham's Law states "Where legal tender laws exist, bad money drives out good money"). A more precise definition is this: "A currency that is artificially overvalued by law will drive out of circulation a currency that is artificially undervalued by that law." Gresham's law is therefore a specific application of the general law of price controls. A common explanation is that people will always keep the less adultered, less clipped, sweated, less filed, less trimmed coin,
Good cop/bad cop Good cop/bad cop "Good cop/bad cop" routine, also called joint questioning or friend and foe, is a psychological tactic used in negotiation and interrogation. "Good cop/bad cop" tactics involve a team of two interrogators who take apparently opposing approaches to the subject. The interrogators may interview the subject alternately or may confront the subject at the same time. The "bad cop" takes an aggressive, negative stance towards the subject, making blatant accusations, derogatory comments, threats, and in general creating antipathy between the subject and himself. This sets the stage for the "good cop" to act sympathetically, appearing supportive and understanding,