3.1 Framework and Assumptions 3.2 Ordinary Least Squares (OLS) Estimation 3.3 Goodness of Fit and Model Selection Criteria 3.4 Consistency and Efficiency of OLS 3.5 Sampling Distribution of OLS 3.6 Variance Estimation for OLS 3.7 Hypothesis Testing 3.8 Applications 3.9 Generalized Least Squares (GLS) Estimation 3.10 Conclusion