If Unbiased :
Linear
yt = α + β1x1 + β2x2t+utZero Conditional Mean of Error
E[ut|xjk]=0No Perfect Collinearity
Homoscedasticity
var(ut|xjk)=δ2No Serial Correlation
cov(ut,us|xjk)=0
If Unbiased :
Linear
yt = α + β1x1 + β2x2t+ut
Zero Conditional Mean of Error
E[ut|xjk]=0
No Perfect Collinearity
Homoscedasticity
var(ut|xjk)=δ2
No Serial Correlation
cov(ut,us|xjk)=0