The origin of the volatility smile phenomenon observed in options markets has eluded the financial world for more than two decades. We provide a new explanation of this phenomenon using a microscopic multi-agent description of markets. In our model individual trading behavior is explicitly...

In this working document, we report on a new approach to high performance simulation. The main inspiration to this approach is the concept of complex systems: disparate elements with well-defined interactions rules and non nonlinear emergent macroscopic behavior. We provide arguments and...

We combine forward investment performance processes and ambiguity averse portfolio selection. We introduce the notion of robust forward criteria which addresses the issues of ambiguity in model specification and in preferences and investment horizon specification. It describes the evolution of...

In quantitative finance, we often model asset prices as a noisy Ito semimartingale. As this model is not identifiable, approximating by a time-changed Levy process can be useful for generative modelling. We give a new estimate of the normalised volatility or time change in this model, which...

This paper presents the first empirical assessment of the causal relationship between social capital and health in Italy. The analysis draws on the 2000 wave of the Multipurpose Survey on Household conducted by the Italian Institute of Statistics on a representative sample of the population (n =...

In this study, we examine how the rice futures market in prewar Japan evolved in light of changes in market efficiency over time. Using a non-Bayesian time-varying VAR model, we compute the time-varying degree of market efficiency of the rice futures exchanges in Tokyo and Osaka. Then, we...

We use the GARCH model with a fat-tailed error distribution described by a rational function and apply it for the stock price data on the Tokyo Stock Exchange. To determine the model parameters we perform the Bayesian inference to the model. The Bayesian inference is implemented by the...

Under proportional transaction costs, a price process is said to have a consistent price system, if there is a semimartingale with an equivalent martingale measure that evolves within the bid-ask spread. We show that a continuous, multi-asset price process has a consistent price system, under...