We show that persistence of conditional volatility in large samples could be exaggerated by the existence of structural breaks in the ARCH and GARCH parameters. Our results suggest that extreme persistence frequently observed in index volatility does not necessarily indicate the same level of...

This paper examines the long-run validity of purchasing power parity (PPP) for four high-inflation countries. The method of Zivot and Andrews (1992) is employed to detect the time-series behavior of the exchange rates and consumer price indices of these countries. We find that these variables...

The sum of squared intraday returns provides an unbiased and almost error-free measure of ex-post volatility. In this paper we develop a nonlinear Autoregressive Fractionally Integrated Moving Average (ARFIMA) model for realized volatility, which accommodates level shifts, day-of-the-week...