![Redundant variables Redundant variables](GUID-A9EE4D6B-3EF4-478E-8218-7B1EFCB7481F-web.png)
Using more than one of these explanatory variables in a single regression model would introduce redundancy and lead to an unstable model. Each explanatory variable in your regression model should get at a different facet of the dependent variable you are trying to predict or model.