This paper studies the properties of high frequency stock trading time using the Trade and Quote Data starting from 1993 to 2002. I show that all these stocks' trading time dynamics exhibit similar temporal patterns: 1) they can be modeled as multifractal processes at large time scales ranging...

This paper, exploiting the properties of mixed causal and noncausal models, proposes strategies to detect time reversibility in stochastic processes. These novel strategies can be implemented to verify the time reversibility of stationary stochastic processes. We show that they can also be used...

Belgium is associated with high-quality chocolate products and Belgian companies play an important role in cocoa processing. However, in historical perspective the global success and reputation of Belgian chocolate is a relatively recent phenomenon. Especially since the 1980s exports of "Belgian...

Antimicrobial resistance (AMR) is currently the focus of much media attention and policy discussion. A historical perspective on AMR suggests that although the challenge of AMR is real, the doomsday tone of most commentary is unwarranted. That is partly because most of the gains in life...