In this paper we consider modeling and forecasting of large realized covariance matrices by penalized vector autoregressive models. We propose using Lasso-type estimators to reduce the dimensionality to a manageable one and provide strong theoretical performance guarantees on the forecast...

This paper features an analysis of the effectiveness of a range of portfolio diversification strategies as applied to a set of daily arithmetically compounded returns on a set of ten market indices representing the major European markets for a nine year period from the beginning of 2005 to the...

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...

This paper focuses on the stability aspects of cross-border banking. We first argue that cross-border banking brings about various benefits and costs for financial stability. Based on this, we draw conclusions for the desirability of cross-border banking in the EU, and derive implications for...

Consider the portfolio problem of choosing the mix between stocks and bonds under a downside risk constraint. Typically stock returns exhibit fatter tails than bonds corresponding to their greater downside risk. Downside risk criteria like the safety first criterion therefore often select corner...

This discussion paper resulted in a publication in the <A href="http://onlinelibrary.wiley.com/doi/10.1111/j.1468-0351.2011.00425.x/abstract;jsessionid=F64011DF99B22B6E2BF33FDA1C47DE9C.f04t03">'Economics of Transition'</A>, 2011, 19(4), 639-666.<P> Whether fiscal policy is sustainable depends on a government's future revenue and expenditure streams, both of which are highly uncertain. In commodity-rich countries, this problem is...</p></a>

This discussion paper resulted in an article in the <I>Journal of the American Statistical Association</I> (2007). Vol. 102, issue 477, pages 16-27.<p> Novel periodic extensions of dynamic long memory regression models with autoregressive conditional heteroskedastic errors are considered for the analysis...</p></i>

This discussion paper led to a publication in the <I>Electronic Journal of Statistics</I> (2014). Vol. 8, pages 1088-1112.<P> We characterize the dynamic properties of Generalized Autoregressive Score (GAS) processes by identifying regions of the parameter space that imply stationarity and ergodicity. We...</p></i>