This paper explores two issues in beta estimation, specifically, time variation and thin trading. In a multivariate GARCH approach, the paper conducts an analysis of the importance of assumptions made about the correlation structure in the multivariate GARCH model. The results of Monte Carlo...

We investigate agency variation in credit quality assessment (Standard and Poor's vs. Moody's vs. Fitch) employing sovereign ratings data for 129 countries, spanning the period 1990 to 2006. While we find that the credit rating agencies often disagree about credit quality, it is usually confined...

We investigate the effects of S&P's sovereign re-ratings on the higher moments of equity market returns over recent financial crises. Using a set of intraday stock market index prices and sovereign credit ratings for a sample of 36 countries which experienced sovereign rating changes over the...

This study investigates the aggregate stock market impact of local currency and foreign currency sovereign rating changes. Consistent with evidence pertaining to company credit rating changes, we report that only rating downgrades have a wealth impact on market returns. Decreases in local...