11.1 The Nature of Heteroscedasticity Homoscedasticity: equal variance Heteroscedasticity: unequal variance HEteroscedasticity is usually found in cross-sectional data VITIA11.1 The Nature of Heteroscedasticity • Homoscedasticity：equal variance. • Heteroscedasticity：unequal variance. Heteroscedasticity is usually found in cross-sectional data