Solve 3 (a) and (c)

3. (a) Distinguish between the terms "conditional variance' and 'unconditional variance. Which of the two is more likely to be relevant for producing i. one-step-ahead volatility forecasts ii. twenty-step-ahead volatility forecasts. (b) If u, follows a GARCH(1,1) process, what would be the likely result if a regression of the form (9.121) were estimated using OLS and assuming a constant conditional variance? (c) Compare and contrast the following models for volatility, noting their strengths and weaknesses: i. Historical volatility ii. EWMA iii. GARCH(1,1) iv. Implied volatility