New and old products differ in two respects: quality and newness. Whereas a higher quality of a new product always benefits consumers, the newness itself benefits some consumers, but not others, and for some, it is even a disadvantage. We capture these features in a Hotelling model of...

The authors develop a dynamic approach to measuring the evolution of comparative brand premium, an important component of brand equity. A comparative brand premium is defined as the pairwise price difference between two products being identical in every respect but brand. The model is based on...

We present a new limit theorem for random means: if the sample size is not deterministic but has a negative binomial or geometric distribution, the limit distribution of the normalised random mean is a t-distribution with degrees of freedom depending on the shape parameter of the negative...

Motivated by repeated spikes and crashes during previous decades we investigate whether the heavily financialized market for crude oil has been driven by speculative bubbles. In our theoretical modeling we draw on the convenience yield approach in order to approximate the fundamental value of...

This paper is about the city size and growth rate distributions as seen from the perspectives of Zipf's and Gibrat's law. We demonstrate that the Gibrat and Zipf views are theoretically incompatible in view of the Fisher-Tippett theorem, and show that the conflicting hypotheses about the size...

The recent introduction of new derivatives with future dividend payments as underlyings allows to construct a direct test of rational bubbles. We suggest a simple, new method to calculate the fundamental value of stock indices. Using this approach, bubbles become observable. We calculate the...

A fundamental component of inter-temporal consumption-saving and portfolio allocation models is a statistical model of the income process. While income processes are commonly unobservable income flows which evolve in continuous time, observable income data are usually discrete, having been...

In case of herding, investors follow each other, prices move together more than they normally do, and the cross-sectional dispersion of returns decreases. Chang, Cheng, and Khorana (2000) suggest to test for herding by regressing the cross-sectional absolute deviation on the absolute and squared...