Question

Why is the average value of the error term zero in a popuplation?

Answer 1

hey dear sweet friend here is your answer

Random chance should determine the values of the error term. For your model to be unbiased, the average value of the error termmust equal zero. ... You don't need to worry about this assumption when you include the constant in your regression model because it forces the mean of the residuals to equal zero.

hope it's help