The study looked at how imbalances in available money in banking systems affect the risk of not having enough cash on hand. They analyzed 224 instances of banks leaving money markets in 54 countries over 20 years. When banks that usually lend money leave, it reduces overall cash available, leading to a shortage. To cope, banks sell off their most easily sold assets, but this can make the problem worse. This imbalance can also reduce the amount of money banks can lend out. The impact is worse for developing countries and before financial crises.