Revisiting the finite mixture of Gaussian distributions with application to futures markets

We present a new estimation method for Gaussian mixture modeling, namely, the kurtosis‐controlled expectation‐maximization (EM) algorithm, which overcomes the limitations of the usual estimation techniques via kurtosis control and kernel splitting. Our simulation study shows that the dynamic allocation of kernels according to the value of the total kurtosis measure makes the proposed kurtosis‐controlled EM algorithm an efficient method for Gaussian mixture density estimation. This algorithm yielded considerable improvements over the classical EM algorithm. We then used the discrete Gaussian mixture framework to account for the observed thick‐tailed distributions of futures returns and applied the kurtosis‐controlled EM algorithm to estimate the distributions of real (agricultural, metal, and energy) and financial (stock index and currency) futures returns. We proved that this framework is perfectly adapted to capturing the departures from normality of the observed return distributions. Unlike in previous studies, we found that a two‐component Gaussian mixture is too poor a model to accurately capture the distributional properties of returns. Similar results have been obtained for stocks, indexes, currencies, interest rates, and commodities. This has important implications in many financial studies using Gaussian mixtures to incorporate the thickness of the tails of the distributions in the computation of the value at risk or to infer implied risk‐neutral densities from option prices, to name but a few. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21: 347–376, 2001     

Digital touch in sponsorship: Getting closer to the brand through virtual reality

Supporters are consuming more and more sporting events through digital platforms. Brands should adapt to these new consumption patterns in order to strengthen their connection with their customers. Today, researchers and practitioners can create more interactive and enjoyable experiences through virtual reality (VR) applications. Through two studies conducted on VR during sporting events, we show that mentally representing the touch experiences of players on the field reduces the psychological distance between the supporter and the player, which strengthens the supporter's attachment to the team and, through the same attachment, to the sponsor (Study 1). We also highlight that these positive effects of VR compared to real touch (using a player's jersey) is linked to the improvement of immersion, which stimulates touch imagery (Study 2). We discuss the implications of this research for theory and practice in the sports business and other sectors.     

The effect of the informal economy on bilateral exports from sub-Saharan African countries

The purpose of this study is to analyse the impact of the informal economy on bilateral exports in sub-Saharan African countries. We use a gravity model, to which we add indicators of the informal economy and indicator variables for different economic regions. The study used Pseudo-Poisson Maximum Likelihood (PPML) and Heckman estimation techniques on data from the period 2002–2018. The results show that the informal economy has a negative impact on bilateral inter-community exports and a positive impact on bilateral intra-community exports. These results thus support the idea that the informal economy can accelerate the integration of regional economic communities and ultimately facilitate the establishment of bilateral export free trade areas at the continental level.