This discussion paper resulted in a publication in 'Quantitative Finance', 2010, 10, 177-194.<P> When using an Euler discretisation to simulate a mean-reverting square root process, one runs into the problem that while the process itself is guaranteed to be nonnegative, the discretisation is not....</p>

At the time of writing this article, Fourier inversion is the computational method of choice for a fast and accurate calculation of plain vanilla option prices in models with an analytically available characteristic function. Shifting the contour of integration along the complex plane allows for...

The characteristic functions of many affine jump-diffusion models, such as Heston’s stochastic volatility model and all of its extensions, involve multivalued functions such as the complex logarithm. If we restrict the logarithm to its principal branch, as is done in most software packages,...

Credit risk models should reflect the observation that the relevant value of collateral is generally not the average value of the asset over all possible states of nature. In most cases, the relevant value of collateral for the lender is its secondary market value in bad states of nature, where...

We derive a model in which a standard international capital asset pricing (ICAPM) model is nested within an ICAPM model with market imperfections. In the latter model an idiosyncratic stochastic factor affects the return of risky assets (over a risk-free rate) on top of the systematic component...

We present a new framework for the joint estimation of the default-free government term structure and corporate credit spread curves. By using a data set of liquid, German mark denominated bonds, we show that this yields more realistic spreads than traditionally obtained spread curves that...

See the article in <I>The North American Journal of Economics and Finance</I> (2013). Volume 26(C), pages 217-226.<P> Research papers in empirical finance and financial econometrics are among the most widely cited, downloaded and viewed articles in the discipline of Finance. The special issue presents...</p></i>

Taking a portfolio perspective on option pricing and hedging, we show that within the standard Black-Scholes-Merton framework large portfolios of options can be hedged without risk in discrete time. The nature of the hedge portfolio in the limit of large portfolio size is substantially different...

Since Black (1976), the source of the stock price volatility smirk has remained a controversy. The volatility smirk is a side effect of agency conflict. An important distinction is that the smirk occurs in the optimum, even after agency conflict has been resolved. The slope of the smirk is found...

This discussion paper resulted in a publication in <Stochastic Models</I> (2012). Volume 28(3), pages 478-502.<P> We apply the splitting method to three well-known counting problems, namely 3-SAT, random graphs with prescribed degrees, and binary contingency tables. We present an enhanced version of the splitting method...</p></stochastic>