bad money drives out good

The phrase "bad money drives out good" is an economic principle known as Gresham's Law. It implies that when there are two types of money in circulation, one of lower quality or value (bad money) and another of higher quality or value (good money), people tend to hoard or spend the bad money while holding onto the good money. This phenomenon occurs because individuals prefer to keep the higher quality currency for its intrinsic value, leaving the lower quality currency in circulation. Over time, the higher quality money becomes scarcer or disappears from circulation, as people prioritize using or exchanging the lower quality money.