The article explores why people don't always spend extra money right away. It suggests that a person's spending habits can be influenced by how much it costs to move money between cash and investments. The study shows that people tend to spend more of unexpected small windfalls than large ones. It also explains why people might not change their spending much when they know they will get a big raise in the future. The research suggests that people try to keep a balance between cash and investments, and this affects how they spend their money.