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Wild Peaks
: If all five hold, OLS has the minimum variance among all linear unbiased estimators. Consistency is the most critical for consistency; if violated, is biased even in large samples.
$$ \textBias = \beta_2 \cdot \delta_1 $$ Where $\beta_2$ is the effect of the omitted variable on $Y$, and $\delta_1$ is the correlation between the included and omitted variable. econometrics exam cheat sheet
