Abstract

Counterfeit Coins and the Geometric Distribution: A Note

Cooper JCB

Currency debasement has been practiced since time immemorial. Such abuse took many forms, ranging from the alloying of gold and silver with other base metals by corrupt heads of state to the filing or clipping of coins by petty criminals. During the period 1285 to 1490, for example, the silver currency of France was debased 123 times and its gold currency 64 times [1]. Today, coins are no longer minted from precious metals, except for a limited number of collectors’/investors’ pieces, but they are still being counterfeited. An interesting case in point is the British £1 coin. The Royal Mint estimates that 1 in 30 of these coins is a fake1. The problem is so acute that, in 2017, a more complex design and metallic composition will be officially introduced to counteract the fraudster.