The denominations of US coins: a case of institutional evolution

The system of denominations of US coins, which the paper treats as a quasi- genetic trait of the US monetary system, has not been constant since incept ion but rather has evolved over time in the sense of being subject to innov ation and selection. However, all the innovations have disappeared, as have a number of the original denominations. Abstract theories of optimal syste ms of denominations provide a good explanation of one selection factor, but other important influences include limiting the number of separate denomin ations and accommodating the requirements of decimal counting. However, eve n some innovations that ultimately disappeared survived for decades.