The Nature of Heteroscedasticity OLS Estimation in the Presence of Heteroscedasticity The Method of Generalized Least Squares (GLS) Consequences of Using OLS in the Presence of Difference between OLS and GLS Detection of Heteroscedasticity Remedial Measures A Concluding Example Summary and Conclusions

12- Autocorrelation The Nature of the Problem OLS Estimation in the Presence of Autocorrelation The BLUE Estimator in the Presence of Autocorrelation Consequences of Using OLS in the Presence of Autocorrelation Detecting Autocorrelation Remedial Measures An Illustrative Example: The Relationship Between Help-Wanted Index and the Unemployment Rate, United States: Comparison of the Methods Autoregressive Conditional Heteroscedasticity (ARCH) Model Summary and Conclusions

14- Econometric Modeling II: Alternative Econometric Methodologies Leamer's Approach to Model Selection Hendry's Approach to Model Selection Selected Diagnostic Test: General Comment Test of Nonnested Hypothesis Summary and Conclusions