Your textbook derives the OLS estimator as = X)-1 Y.
Show that the estimator does not exist if there are fewer observations than the number of explanatory variables,including the constant.What is the rank of X in this case?

Question

Your textbook derives the OLS estimator as  =  X)-1  Y.
Show that the estimator does not exist if there are fewer observations than the number of explanatory variables,including the constant.What is the rank of  X in this case?

Quizplus · Accepted Answer

The Answer of Your textbook derives the OLS estimator as  =  X)-1  Y.
Show that the estimator does not exist if there are fewer observations than the number of explanatory variables,including the constant.What is the rank of  X in this case?

Your Textbook Derives the OLS Estimator as =