Ideal conditions for OLS analysis Data types Pooled data Cross section Time serⅰes. Panel data OLS (AlLinearity (A2)Strict Exogeneity (A3)Full Rank Multicollinearity A4)Spherical errors: Heteroskedasticity (A5 Normal errors: MLE Maximum Likelihood Methods) OLS: GLS: WLSIdeal conditions for OLS analysis • Data types. • Pooled data. • Cross section. • Time series. • Panel data. • OLS. • (A1)Linearity. • (A2)Strict Exogeneity. • (A3)Full Rank: Multicollinearity. • (A4)Spherical errors: Heteroskedasticity. • (A5)Normal errors: MLE (Maximum Likelihood Methods) • OLS: GLS; WLS; 6