Multidimensional quasi-Monte Carlo Malliavin Greeks

The aim of this paper is extensively investigate the performance of the estimators for the Greeks of multidimensional complex path-dependent options obtained by the aid of Malliavin Calculus. The study analyses both the computation effort and the variance reduction in the Quasi-Monte Carlo simulation framework. For this purpose, we adopt the approach employed by Montero and Kohatsu-Higa to the multidimensional case. The multidimensional setting shows the convenience of the Malliavin Calculus approach over different techniques that have been previously proposed. Indeed, these techniques may be computationally expensive and do not provide enough flexibility for variance reduction. In contrast, the Malliavin approach provides a class of functions that return the same expected value (the Greek) with different accuracies. This versatility for variance reduction is not possible without the use of the generalized integral by part formula of Malliavin Calculus. In the multidimensional context, we find convenient formulas that permit to improve the localization technique, introduced in Fournié et al. and reduce both the computational cost and the variance. Moreover, we show that the parameters for the variance reduction can be obtained on the flight in the simulation. We illustrate the efficiency of the proposed procedures, coupled with the enhanced version of Quasi-Monte Carlo simulations as discussed in Sabino, for the numerical estimation of the Deltas of call, digital Asian-style and exotic basket options with a fixed and a floating strike price in a multidimensional Black-Scholes market. Given the fact that the gammas of a call option coincides, apart from a constant, with the deltas of digital options, this setting also covers the analysis of formulas tailored for the second order Greeks of call options.     

Output gap in Brazil: a real-time data analysis

Recent literature for developed economies has shown that output gap estimates go through important revisions over time, impairing their reliability in real time. We organize a real-time data set for Brazil’s GDP and assess the revisions of the output gap estimated by four different methods. Similar to the findings of studies for developed economies, the output gap revisions in Brazil are substantial in all methods, with frequent changes in the output gap sign. In general, both the GDP data revision and the effect of adding new observations to the sample are relevant sources of output gap revisions. However, differently from those studies, we cannot assert that the latter source is preponderant.     

Efficient quasi-Monte simulations for pricing high-dimensional path-dependent options

Quasi-Monte Carlo method (QMC) is an efficient technique for numerical integration. QMC provides a lower convergence rate, O(ln ^d n/n), than the standard Monte Carlo (MC), , where n is the number of simulations and d the nominal problem dimension. However, some studies in the literature have claimed that the QMC performs better than the MC method for d < 20/30 because of its dependence on d. Caflisch et al. (J Comput Finance 1(1):27–46, 1997) have proposed to extend the QMC superiority by ANOVA considerations. To this aim, we consider the Asian basket option pricing problem, where d is much higher than 30, by QMC simulation. We investigate the applicability of several path-generation constructions that have been proposed to overtake the dimensional drawback. We employ the principal component analysis, the linear transformation, the Kronecker product approximation and test their performance both in terms of computational cost and accuracy. Finally, we compare the results with those obtained by the standard MC.      

Correlating Lévy processes with self-decomposability: applications to energy markets

Decisions in Economics and Finance - Based on the concept of self-decomposability, we extend some recent multidimensional Lévy models built using multivariate subordination. Our aim is to...     

Women leaders—challenges,successes, and other insights from the top

The reasons for the persistent lag of women as leaders are complex. Attrition is an issue for women for many reasons, including traditional gender roles that may affect how women are perceived and the choices they have available (or they make), a lack of role models, the undervaluing of women's traditional communication and leadership styles, and organizational culture. Within medicine (clinical environments) and academic medicine (medical school and clinical environments), it is clear that the lack of women in leadership positions is more than a pipeline or a labyrinth problem. We undertook this case study to better understand the current challenges experienced by women aspiring to leadership positions in medicine and academic medicine. What types of challenges do women face as they move up in an academic or medical environment? And which challenges impact more than others in attaining leadership roles in these organizations: race and ethnicity, differences in leadership style and skills, mentorship and network, life experiences and family responsibilities, organizational culture, or gender? Our study addresses a gap in the literature by examining the leadership experiences of eight successful women in the fields of medicine and academic medicine. The emerging insights from these leaders may be useful for women from diverse backgrounds aspiring to be senior leaders in the future.     

Exploring the black box in Spanish firms: the effect of the actual and perceived system on employees' commitment and organizational performance

Several studies in strategic human resource management have described a relationship between people-management practices and organizational performance. However, the mediating processes that explain such a relationship remain unexplored. This study examines how both the actual people-management system (assessed by managers) and the perceived system (assessed by employees) influence employees' commitment, and how this in turn contributes to employee and organizational outcomes. Multilevel analyses of a sample of 732 employees from 26 Spanish small and medium-sized enterprises (SMEs) supported a model in which employees' commitment mediates between the actual system and unit-level absenteeism, which in turn has an effect on productivity. Results also showed the importance of the perceived system in attempting to understand the true effect of the actual system on employees' commitment to the organization.     

Forward or backward simulation? A comparative study

The aim of this study is to present algorithms for the backward simulation of standard processes that are commonly used in financial applications. We extend the works of Ribeiro and Webber and Avramidis and L'Ecuyer on gamma bridge and obtain the backward construction of a gamma process. In addition, we are able to write a novel acceptance–rejection algorithm to simulate the Inverse Gaussian (IG) bridge and consequently, the IG process backward in time. Therefore, using the time-change approach, we can easily derive the backward generation of the compound Poisson with infinitely divisible jumps, the Variance-Gamma the Normal-Inverse-Gaussian processes and subsequently the time-changed version of the Ornstein–Uhlenbeck process introduced by Li and Linesky. We then compare the performance of the forward and backward construction of all these processes and show that the latter one is the preferable solution in the context of pricing American options or energy facilities like gas storages.