why would one use a multiple regression over a simple ols regression 
a dependent variable is rarely explained by only one variable in such cases an analyst uses multiple regression which attempts to explain a dependent variable using more than one independent variable the model however assumes that there are no major correlations between the independent variables can i do a multiple regression by hand it s unlikely as multiple regression models are complex and become even more so when there are more variables included in the model or when the amount of data to analyze grows to run a multiple regression you will likely need to use specialized statistical software or functions within programs like excel 