German South West African Mark the gold content of the British Pound Sterling was 7.3224 grams, while the gold content of 20 marks was 7.168 grams. According to Gresham's Law, "bad money drives out good", so the "bad" Mark replaced the "good" British Pound Sterling. In 1901, the German Mark became the official currency of German South West Africa, hence replacing the 20 and 5 mark denominations of the German South West African Mark, for which they were also demonetized (although, they continued use in the metropolis of German South West Africa until 1907). In 1923, the coins of the German South West African Mark
Say's law real shocks cause recessions and that the market responds efficiently to these real economic shocks. Paul Krugman dismisses Say's law as, "at best, a useless tautology when individuals have the option of accumulating money rather than purchasing real goods and services". It is not easy to say what exactly Say's law says about the role of money apart from the claim that recession is not caused by lack of money. The phrase "products are paid for with products" is taken to mean that Say has a barter model of money; contrast with circuitist and post-Keynesian monetary theory. One can read