110 likes | 210 Views
Fin250f: Lecture 5.2 Fall 2005 Reading: Taylor, chapter 9. Volatility Models. Outline. Stochastic volatility models ARCH(1) GARCH(1,1) GARCH(p,q) GJR and volatility asymmetry. Stochastic Volatility. Stochastic Volatility. Very straightforward Difficult to estimate Extensions:
E N D
Fin250f: Lecture 5.2 Fall 2005 Reading: Taylor, chapter 9 Volatility Models
Outline • Stochastic volatility models • ARCH(1) • GARCH(1,1) • GARCH(p,q) • GJR and volatility asymmetry
Stochastic Volatility • Very straightforward • Difficult to estimate • Extensions: • h(t) follows discrete markov process
ARCH(1) • Alpha<1 • Omega>0 • Squared return correlations not persistent enough
GARCH(1,1) • Most heavily used volatility model on Wall St. • Estimation: • maximum likelihood (not too difficult) • Moments • Variance • Skew = 0 • Kurtosis > 3