# Multiple Regression independent variables

I have a relative straight forward question.

Lets say we have a typical multiple regression model. With lets say 3 different independent variables. If one independent variable with its beta parameter has a very low value compared to the other parameters, lets say 0.00025.

Would it be better to not include this variable in the model?

/Peter

$$\log y = 5.32 + 0.3\log(x_1) +0.15(x_2) + 0.00025(x_3) + u$$ where y is measured in pounds and the independent variables are measured in percentages.

• That must depend on what the purpose of your model is, what the scale of that variable is, what the relationship between the predictor variables is. – mdewey Nov 16 '16 at 15:26
• okej @mdewey I've added a more specific model, does this help? – user358065 Nov 16 '16 at 15:32
• my theory is that we can omit x_3 since, it has such a small effect on logy. – user358065 Nov 16 '16 at 15:39