This paper introduces a time-varying threshold autoregressive model (TVTAR), which is used to examine the persistence of deviations from PPP. We find support for the stationary TVTAR against the unit root hypothesis; however, for some developing countries, we do not reject the TVTAR with a unit...

This paper examines whether deviations from PPP are stationary in the presence of nonlinearity, and whether the adjustment toward PPP is symmetric from above and below. Using alternative nonlinear models, our results support mean reversion and asymmetric adjustment dynamics. We Find differences...

Statistical measures of the volatility of exchange rates, interest rates, and stock prices are estimated for a number of countries. Periods of high volatility are identified and compared with periods of financial difficulty. The results indicate that GARCH models of volatility could be...