I will attach my question.

Exercise 12.13 Consider the structural equation .Yi = I'D-r +xi'gi2 +i E[ziei}=[} where .172; is 1:2 x l and treated as endogenous. The variables z; = {Ill-Jag) are treated as exogenous, where 2:2; is 2 x 1 and 2 2 k3. You are interested in testing the hypothesis Consider the reduced form equation for y;- y;- = xii?\" + arm-112 + 0;. [12.99] Show how to test I-u using only the OLE estimates of (12.99}. Hint: This will require an analysis of the reduced form equations and their relation to the structural equation