The study looked at how new rules about how much money banks need to keep on hand might affect how risky they are. By using data from banks in the 1980s and 1990s, the researchers found that making banks have more money in reserve could actually make them take on more risky investments. They also found that giving banks rewards for having more money in reserve doesn't always stop them from taking risks. However, if the rules about how much money banks need to keep are strict enough, it could help make banks safer.