TY - JOUR AU - Calvet,Laurent AU - Fisher,Adlai TI - Regime-Switching and the Estimation of Multifractal Processes JF - National Bureau of Economic Research Working Paper Series VL - No. 9839 PY - 2003 Y2 - July 2003 UR - http://www.nber.org/papers/w9839 L1 - http://www.nber.org/papers/w9839.pdf N1 - Author contact info: Laurent E. Calvet Department of Finance HEC Paris 1 rue de la Libération 78351 Jouy en Josas France Tel: +33 13 967 9409 Fax: +33 13 967 7085 E-Mail: calvet@hec.fr Adlai Fisher Sauder School of Business University of British Columbia 2053 Main Mall, Vancouver BC, CANADA V6T 1Z2 Tel: 604 822 8331 Fax: 604 822 4695 E-Mail: adlai.fisher@sauder.ubc.ca AB - We propose a discrete-time stochastic volatility model in which regime switching serves three purposes. First, changes in regimes capture low frequency variations, which is their traditional role. Second, they specify intermediate frequency dynamics that are usually assigned to smooth autoregressive processes. Finally, high frequency switches generate substantial outliers. Thus, a single mechanism captures three important features of the data that are typically addressed as distinct phenomena in the literature. Maximum likelihood estimation is developed and shown to perform well in finite sample. We estimate on exchange rate data a version of the process with four parameters and more than a thousand states. The estimated model compares favorably to earlier specifications both in- and out-of-sample. Multifractal forecasts slightly improve on GARCH(1,1) at daily and weekly intervals, and provide considerable gains in accuracy at horizons of 10 to 50 days. ER -