National Research University Higher School of Economics

This paper gives a survey of recent investigations on nonlinear Fokker-Planck-Kolmogorov equations of elliptic and parabolic types and contains a number of new results. We discuss in detail the problems of existence and uniqueness of solutions, various estimates of solutions, connections with linear equations, and the convergence of solutions of parabolic equations to stationary solutions. Bibliography: 116 items.

This paper examines the role of foreign exchange reserve demand in mitigating inflationary pressures resulting from money supply growth in reserve currency issuing states (RCISs). Despite recurrent substantial monetary expansions in RCISs in response to recessions such as the 2000 Post-Dot Com Bubble, the 2008 Great Recession, and the 2020 Covid-19 pandemic-induced recession, RCISs have not experienced commensurate inflation. Within the framework of the Quantity Theory of Money (QTM), factors such as economic slowdown and reduction in the velocity of money may contribute to dampening inflationary pressure that stems from money supply growth; however, GDP slowdowns have not explained the disproportionally low inflation in RCISs compared to their monetary expansions, and the impact of reduction in the velocity on lowering inflation remains unclear due to limited real-world data. In contrast, there is reliable data for foreign exchange reserve demand, characterized by currency exports in exchange for real economic resources of equivalent value. By analyzing the relationship between money supply growth, foreign exchange reserve demand, and inflation within the framework of QTM, this paper introduces the foreign exchange reserve demand-inflation buffer hypothesis. The theoretical and empirical investigation sheds light on the role of foreign exchange reserve demand in moderating inflationary pressures in RCISs.

This study investigates the influence of Reddit community on Bitcoin market performance by introducing the Reddit Sentiment Index (RedditSI) as a tool to measure sentiment among Reddit users. The index was crafted based on the Bitcoin-related subreddits and classified with the Flair NLP model. Statistical analysis, including correlation, cointegration and causality tests, revealed significant relationships between RedditSI and BTC exchange characteristics (price, returns, absolute returns, volatility and volume), both in the short and long term. The findings highlight the importance of ongoing sentiment monitoring for investors, regulators and researchers to better understand the link between human psychology and cryptocurrency markets.

Bipolar disorder (BD) involves altered reward processing and decision-making, with inconsistencies across studies. Here, we integrated hierarchical Bayesian modelling with magnetoencephalography (MEG) to characterise maladaptive belief updating in this condition. First, we determined if previously reported increased learning rates in BD stem from a heightened expectation of environmental changes. Additionally, we examined if this increased expectation speeds up belief updating in decision-making, associated with modulation of rhythmic neural activity within the prefrontal, orbitofrontal, and anterior cingulate cortex (PFC, OFC, ACC). Twenty-two euthymic BD and 27 healthy control (HC) participants completed a reward-based motor decision-making task in a volatile setting. Hierarchical Bayesian modelling revealed BD participants anticipated greater environmental volatility, resulting in a more stochastic mapping from beliefs to actions and paralleled by lower win rates and a reduced tendency to repeat rewarded actions than HC. Despite this, BD individuals adjusted their expectations of action-outcome contingencies more slowly, but both groups invigorated their actions similarly. On a neural level, while healthy individuals exhibited an alpha-beta suppression and gamma increase during belief updating, BD participants showed dampened effects, extending across the PFC, OFC, and ACC regions. This was accompanied by an abnormally increased beta-band directed information flow in BD. Overall, the results suggest euthymic BD individuals anticipate environmental change without adequately learning from it, contributing to maladaptive belief updating. Alterations in frequency-domain amplitude and functional connectivity within the PFC, OFC, and ACC during belief updating underlie the computational effects and could serve as potential indicators for predicting relapse in future research.

We explore the fundamental principles underlying the architecture of the human brain’s structural connectome through the lens of spectral analysis. Building on the idea that the brain balances efficient information processing with minimizing wiring costs, we aimed to understand how the connectome metric properties relate to the presence of an inherent scale. We demonstrate that a simple generative model, combining nonlinear preferential attachment with an exponential penalty for spatial distance, can effectively reproduce several key features of the human connectome. These include spectral density, eigenmode localization, local clustering and topological properties. Additionally, we examine the finer spectral characteristics of human structural connectomes by evaluating the inverse participation ratios across various parts of the spectrum. Our analysis shows that the level statistics in the soft cluster region of the Laplacian spectrum deviate from a Poisson distribution due to interactions between clusters. Furthermore, we identify localized modes with large IPR values in the continuum spectrum. Multiple fractal eigenmodes are found across the spectrum, and we evaluate their fractal dimensions. We also find a power-law behavior in the return probability, a hallmark of critical behavior. We conclude by discussing the conjecture that the brain operates in an extended critical phase that supports multifractality.

Forging government-business relationships is an important prerequisite for a country’s economic system to function efficiently. In sustainable development, such cooperation is especially relevant as the state is one of the key stakeholders for business survival and responsible corporate activities contribute to the achievement of national sustainability goals. The study identifies government relations (GR) management tools that are instrumental in successful implementation of ESG practices and investigates the relationship between GR management as a formalized function and the effectiveness of sustainable develop ment practices in Russian companies. Stakeholder theory constitutes the methodological basis of the study. The key research methods are correlation analysis and one-way analysis of variance (ANOVA). The data set of the study is represented by data from 86 largest Russian companies from the RAEX TOP-100 ESG Ranking as of December, 2023. The top tier companies demonstrate better financial performance and tend to single out GR as a separate function (division). System relationships between big busi ness and the state produce an overall positive effect in society and allow achieving financial stability. The larger the business and the scale of a company’s ESG projects, the greater the need for coordinated actions to reduce potential risks and losses. At the same time, cross-functional interaction between GR and other divisions of the firm enhances the effectiveness of its ESG practices. The findings prove that implementing the GR function is important for both private businesses and companies partially owned by the state.

p>The development of the Internet, along with the improvement of patients’ digital skills, makes them competent in some matters of medical care. The aim of this study was to adapt the Online Health Information Seeking Scale in the Russian-speaking sample with the establishment of relationships with such cyber phenomena as doomscrolling, cyberchondria, and social media addiction. In an all-Russian online survey conducted using the service Toloka.AI, 1,025 people took part. The toolkit included the following questionnaires: the Online Health Information Seeking Scale (OHISS), the Doomscrolling Scale (DS), the Cyberchondria Severity Scale (CSS), the Bergen Social Media Addiction Scale (BSMAS). The results showed that the Russian version of the OHISS has a one-factor structure and high internal consistency (Cronbach’s α = 0.845; Mc’Donald’s ω = 0.847). The OHISS scores were statistically significantly positively correlated with scores of doomscrolling, cyberchondria, and social media addiction. The online health information seeking was not related to the age of the respondents, their income level and education level. Women, respondents who are married and separated, and respondents who consider themselves to be quite religious were exposed to more frequent online searches for health information. Empirical data obtained using the Online Health Information Seeking Scale allow us to consider the adapted scale as a psychometrically sound diagnostic instrument and recommend it for solving practical and research tasks.</p