試題詳解

5. Suppose a population regression equation is: Y_i=β₀ +β₁X_i +u_i. Y_i, X_i, and ui denote the dependent variable, independent variable, and the error term, respectively. i indexes cach individual observation. Which of the following statement is correct?
(A) Ifand the correlation between X_i and u_i is zero, the OLS estimator is unbiased.
(B) If and the correlation between X_i； and u_i； is zero, the OLS estimator  is inconsistent.
(C) , the correlation between Xi and ue may not be zero.
(D) The assumption that the correlation between X_i and u_i is zero cannot be tested empirically.
(E)None of the above choices (a)-(d).