Bank runs are often described as "self-fulfilling prophecies." Why is this phrase appropriate to bank runs?

A self-fulfilling prophecy is a prediction or belief about a future event that, once it gains enough momentum or influence, causes the event to occur as predicted. This phenomenon occurs because the belief affects individuals' actions and decision-making, directly leading to the predicted outcome.

Banks operate using a system called fractional reserve banking, wherein they hold only a portion of deposited funds in reserve and loan out the rest. In simplified terms, when a customer deposits money in the bank, the bank can use a percentage of that amount (referred to as the reserve ratio) to make loans and generate profits from the interest. Hence, banks rely on a steady inflow of deposits and a stable number of withdrawals to maintain their operations and ensure they have sufficient reserves to meet depositors' demands for withdrawals.

A bank run occurs when a large number of depositors, due to fear or distrust in the bank's solvency, decide to withdraw their funds simultaneously. This rush of withdrawals could be triggered by various factors like poor financial reports, economic downturns, or rumors circulating about the bank's health. Since the bank only has a portion of its deposited funds in reserve, it might struggle to meet the immediate demand for cash during a bank run.

Bank runs are often described as self-fulfilling prophecies because they can lead to the underlying issue they were initially triggered by. When depositors fear that a bank is insolvent and collectively withdraw their money, this sudden rush of withdrawals may cause undue strain on the bank and significantly impact its liquidity. The bank may become unable to satisfy customers' needs for cash, sell its assets at a lower price than actual value, or even close its doors, eventually becoming insolvent when, in reality, it may not have been in such dire straits without the bank run in the first place. Therefore, the belief or fear that the bank is insolvent ultimately led to the fulfillment of the prophecy by causing the very outcome the depositors tried to avoid. Thus, the phrase "self-fulfilling prophecy" is appropriate to bank runs as the fear and actions of the depositors, based on a belief about the bank's solvency, might lead to the actualization of that belief, even if it was not initially true.