
\subsection{Gauss-Markov theorem}

Mean of errors zero
+ If the model should only have errors on upside or downside for some reason, OLS will not provide this.

Homoscedastic (all have the same variance)	
+ The results aren’t biased, but variances etc are

Errors are uncorrelated
+ (this would mean you should add lagged variables etc)

show bias from each GM violation

OLS is BUE under normally distributed errors

OLS is BLUE for non-normally distribed errors

