Using a limiting approach to portfolio credit risk, we obtain analytic expressions for the tail behavior of the distribution of credit losses. We show that in many cases of practical interest the distribution of these losses has polynomial ('fat') rather than exponential ('thin') tails. Our...

We investigate the potential presence of time variation in the coefficients of the ''Fama regression'' for Uncovered Interest Rate Parity. We implement coefficient constancy tests, rolling regression techniques, and stochastic coefficient models based on state space modelling. Among six major US...

We investigate the potential presence of time variation in the coefficients of the ''Fama regression'' for Uncovered InterestRate Parity. We implement coefficient constancy tests, rolling regression techniques, and stochastic coefficient modelsbased on state space modelling. Among six major US...

Using a limiting approach to portfolio credit risk, we obtain analyticexpressions for the tail behavior of the distribution of credit losses. We showthat in many cases of practical interest the distribution of these losses haspolynomial ('fat') rather than exponential ('thin') tails. Our...

Exchange rate returns are fat-tailed distributed. We provide evidence that the apparent non-normality derives from the behavior of macroeconomic fundamentals. Economic and probabilistic arguments are offered for such a relationship. Empirical support is given by testing against normality and...

The dynamic properties of micro based stochastic macro models are often analyzed through a linearization around the associated deterministic steady state. Recent literature has investigated the error made by such a deterministic approximation. Complementary to this literature we investigate how...

We advocate the use of absolute moment ratio statistics in conjunctionwith standard variance ratio statistics in order to disentangle lineardependence, non-linear dependence, and leptokurtosis in financial timeseries. Both statistics are computed for multiple return horizonssimultaneously, and...

Standard risk metrics tend to underestimate the true risks of hedge funds becauseof serial correlation in the reported returns. Getmansky et al. (2004) derive mean,variance, Sharpe ratio, and beta formulae adjusted for serial correlation. Followingtheir lead, adjusted downside and global...

Actual portfolios contain fewer stocks than are implied by standard financial analysis that balances the costs of diversification against the benefits in terms of the standard deviation of the returns. Suppose a safety first investor cares about downside risk and recognizes the heavytail feature...

Portfolio risk is in an important way driven by 'abnormal' returns emanating from heavy tailed distributed asset returns. The theory of regular variation and extreme values provides a model for this feature of financial data. We first review this theory and subsequently study the problem of...