Notes And Ideas

Question 1

Simple vs multiple linear regression

Answer 1

Always follow simple linear regression on two or more independent variables with multiple
Because you may see correlation between an independent variable and the dependent variable, but that correlation can disappear when each is held constant.
Example is temperature correlation with ice cream sales and people wearing shorts correlation with ice cream sales.
While both are correlated using simple regression, by using multiple linear regression, you see that shorts are actually not driving ice cream sales, but are correlated with temperature, which drives both.