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 investigates whether there is evidence of structural change in the Brazilian term structure of interest rates. Multivariate cointegration techniques are used to verify this evidence. An econometrics model is estimated and is a Vector Autoregressive Model with Error Correction...

Markowitz optimization plays an important role in modern portfolio theory. However, it is well-known that Markowitz optimization is highly affected by the estimation error of the mean vector and covariance matrix, resulting in extreme and/or unrealistic portfolio weights, lacks of...

Usually, inflation is optimally forecasted using simple time series models or a Phillips' curve process. However, as more people become online shoppers, ``online inflation'' turns out to be a good predictor of official inflation too. Online prices can be obtained at a higher frequency than...

This article investigates the existence of contagion between countries on the basis of an analysis of returns for stock indices over the period 1994 to 2003. The econometrics methodology used is that of multivariate Generalized Autoregressive Conditional Heteroscedasticity (GARCH) family...