Instrumental variable

An instrumental variable is like a tool that helps scientists learn about two things that are linked together. Scientists can use the instrumental variable to measure how one thing affects another. For example, imagine you want to know how eating chocolate affects a person's happiness. Without an instrumental variable, it would be hard to measure how much eating chocolate affects a person's happiness. But if you use the instrumental variable of how much people enjoy the taste of chocolate, you could use this to measure how much eating chocolate affects a person's happiness. The instrumental variable helps scientists to get a better idea of how different things are related.