In Example 10.6, we estimated a variant on Fair's model for predicting presidential election outcomes in the United States.
(i) What argument can be made for the error term in this equation being serially uncorrelated? (How often do presidential elections take place?)
(ii) When the OLS residuals from (10.23) are regressed on the lagged residuals, we obtain  = -.068 and se() = .240. What do you conclude about serial correlation in the up?
(iii) Does the small sample size in this application worry you in testing for serial correlation?