For each of the following statements, answer “agree” or “disagree,” and provide justification.
(i) “Omitting a relevant variable from a regression model generally causes bias in the OLS estimators.”
(ii) “Because the OLS estimators are unbiased under Assumptions SLR.1 to SLR.4, the residuals are always equal to the errors: uˆ u ,i 1,...,n. i = i =
(iii) “If the R-squared from a simple regression is less than .50, the OLS estimators are probably biased.”