A Study of the Allan Variance for Constant-Mean Non-Stationary Processes

The Allan Variance (AV) is a widely used quantity in areas focusing on error measurement as well as in the general analysis of variance for autocorrelated processes in domains such as engineering and, more specifically, metrology. The form of this quantity is widely used to detect noise patterns and indications of stability within signals. However, the properties of this quantity are not known for commonly occurring processes whose covariance structure is non-stationary and, in these cases, an erroneous interpretation of the AV could lead to misleading conclusions. This paper generalizes the theoretical form of the AV to some non-stationary processes while at the same time being valid also for weakly stationary processes. Some simulation examples show how this new form can help to understand the processes for which the AV is able to distinguish these from the stationary cases and hence allow for a better interpretation of this quantity in applied cases

The impact of humanitarian disaster on the working approach of accountants: a study of contingent effects

Purpose – The purpose of this paper is to investigate how a humanitarian disaster as coronavirus disease 2019 (COVID-19) shapes the working approach of accountants. This research is motivated by the call for more in-depth analyses of how COVID-19 affects the work, role and human condition of accountants. The study aims to discover the contingent effects, based on the contingency theory, on accountants’ work due to a disaster like COVID-19. Design/methodology/approach – This is a qualitative study with an action research approach. The research relies on semi-structured interviews and the active participation of a co-author in a professional organisation under investigation. Data collected are analysed using thematic analysis through an inductive interpretative approach. Findings – The contingent shock embodies both a reactive and adaptive approach in the accountants’ professional work. From a theoretical perspective, this study identifies nine contingent phases related to shock. The accountants’ experience helps to understand how the COVID-19 pandemic contingently shapes the working approach of accountants with both short- and long-term organisational implications. Originality/value – Based on the literature survey, this is the first study to adopt an action research approach to engage with the complex dynamics involved in the social context of COVID-19 by discovering the effective actions, reactions, changes and solutions to problems experienced by professional accountants. This approach helps to build knowledge that enhances professional, and community practises by answering the call for multidisciplinary contributions in accounting to address the global COVID-19 crisis, its impacts and opportunities for future research