What would happen if i run a linear regression model on a data set having some missing values?
It depends on the number of missing values. Running the analysis with missing values may lead to loose some importance of the variables.
- Impute the missing values with any one of the imputation methods
- Delete the missing records if it is not important
- Get better data (if possible)
Tools handle missing values. But in terms of math behind the linear regression while estimating say for a simple y=a+bx, a and b are calculated with a formula that requires no missing values as its a minimization function.
If you run in an excel with missing values, i doubt if you will be able to find each value that is required in the formula unless you consider the missing to be 0 or treat them or simply delete them.