As valuation analysts, we often analyze how one or more variables explain the behavior of another variable such as revenues or trends in market multiples. We are also tasked with analyzing trends in data over time to be used as a basis for a forecast of future expected results. A tool that helps us analyze the relationships between variables is linear regression. Linear regression models can be useful tools in analyzing relationships between economic and financial variables over time and using these relationships as a basis to support various assumptions in business valuation. However, analysts need to be aware of the various assumptions and shortcomings of linear regression models.