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 and in general showing sympathy for the subject. The good cop will also defend the subject from the bad cop. The subject may feel they can cooperate with the good cop either out of trust or out of fear of the bad cop. They may then seek protection by and trust the good cop and provide the information the interrogators are seeking. This technique also has its disadvantages in that it can be easily identified and the "bad cop" may alienate the subject. Good cop/bad cop "Good cop/bad cop" routine, also called joint questioning or friend and foe, is a