What are the two conditions for omitted variable bias?Based on the answer above, are our OLS estimators biased or unbiased? Give short explanations.

We are given a sample of n observations that satisfy the following regression model Yi = Bo + BIXli + B2Xzi + B3X3i + Ui, for all i = 1, . .., n. This model fulfills the Least-Squares assumptions. Moreover, we also know that Cov(Xli, Xsi) = Cov(X2i, X3i) = 0. We obtain OLS estimators of {B1, B2, 83} separately from the following regressions Yi = Bol + BIXli + B2Xzi + Uli, (M1 ) Yi =Boz + B3Xsi + Uzi, (M2) where both models satisfy the least-squares assumptions. 1. What are the two conditions for omitted variable bias? image.png 2. Based on your previous answer, are our OLS estimators biased or unbiased? Give a short explanation. Drop files or click here to upload MacBook Pro esc Q O @ # $