In economics, Gresham's law is a monetary principle stating that "bad money drives out good". For example, if there are two forms of commodity money in circulation, which are accepted by law as having similar face value, the more valuable commodity will gradually disappear from circulation.[1][2] The law was named in 1860 by economist Henry Dunning Macleod after Sir Thomas Gresham (1519–1579), an English financier during the Tudor dynasty. Gresham had urged Queen Elizabeth to restore confidence in then-debased English currency. The concept was thoroughly defined in medieval Europe by Nicolaus Copernicus and known centuries earlier in classical Antiquity, the Middle East and China.

onversation among groups ofreaders over time.

when Britannica conducted followup research on whether or not the books were actually being read, they found that buyers who really read the books were the exception. The two largest sub-categories among buyers who were more likely to have read the books were housewives and men trained in some sort of technical profession.