Hasil untuk "Economic theory. Demography"

Michael Balzer, Kainat Khowaja, Christiane Fuchs

Surveillance of diseases in a pandemic is an important part of public health policy. Diagnostic testing at the individual level is often infeasible due to resource constraints. To circumvent these constraints, group testing can be applied. The economic cost evaluation from the payer's perspective typically focuses only on deterministic costs which overlooks the substantial economic impact of productivity losses resulting from quarantine and workplace disruptions. The objective of this article is to develop a mathematical model for a retrospective economic evaluation of group testing that incorporates both deterministic costs and income-based economic loss. Group testing algorithms are revisited and simulated at optimized pool sizes to determine the required number of tests. Income data from the German Socio-Economic Panel are integrated into a mathematical model to capture the economic loss. Afterward, hybrid Monte Carlo experiments are conducted by evaluating the economic cost in the Coronavirus disease 2019 pandemic in Germany. Monte Carlo experiments show that the optimal choice of group testing algorithms changes substantially when income-based economic losses are included. Evaluations considering only deterministic costs systematically underestimate the total economic cost. Algorithms with a longer quarantine duration are less attractive than shorter quarantine duration if income-based economic loss is accounted for. The findings show that current evaluations underestimate the true economic cost. Group testing algorithms with shorter duration and fewer stages are preferred, even when they require a larger number of tests. These results underscore the importance of incorporating income-based economic loss into a mathematical model.

Joe Gildea

We complete the foundational architecture of Algebraic Phase Theory by developing a categorical and $2$-categorical framework for algebraic phases. Building on the structural notions introduced in Papers~I-III, we define phase morphisms, equivalence relations, and intrinsic invariants compatible with the canonical filtration and defect stratification. For finite, strongly admissible phases we establish strong rigidity theorems: phase morphisms are uniquely determined by their action on rigid cores, and under bounded defect, weak, strong, and Morita-type equivalence all coincide. In particular, finite strongly admissible phases admit no distinct models with the same filtered representation theory. We further show that structural boundaries are invariant under Morita-type equivalence and therefore constitute genuine categorical invariants. Algebraic phases, phase morphisms, and filtration-compatible natural transformations form a strict $2$-category in the strongly admissible regime. We also prove that completion defines a reflective localization of this category, with complete phases characterized as universal forced rigidifications. Together, these results elevate Algebraic Phase Theory from a collection of algebraic constructions to a categorical framework in which rigidity, equivalence collapse, boundary invariance, and completion arise as intrinsic consequences of phase interaction, finiteness, and admissibility.

Emanuele Mendicelli, Georg Bergner, Masanori Hanada

Simulating lattice gauge theories on quantum computers presents unique challenges that drive the development of novel theoretical frameworks. The orbifold lattice approach offers a scalable method for simulating SU($N$) gauge theories in arbitrary dimensions. In this work, we present three improvements: (i) two new simplified Hamiltonians, (ii) an encoding of the SU(2) theory with smaller number of qubits, and (iii) a reduction in the requirement for large scalar masses to reach the Kogut-Susskind limit, achieved via the inclusion of an additional term in the Hamiltonian. These advancements significantly reduce circuit depth and qubit requirements for quantum simulations. We benchmarked these improvements using Monte Carlo simulations of SU(2) in (2+1) dimensions. Preliminary results demonstrate the effectiveness of these developments and further validate the use of noncompact variables as a promising framework for scalable quantum simulations of gauge theories.

Conghao Zhu, Tingting Wang

Against the backdrop of China's growing emphasis on corporate ESG performance and the prevalence of involutional competition within industries, this study examines the impact of new firm entry on the ESG performance of incumbent firms, using panel data from Chinese A-share listed companies spanning 2008 to 2022. The results reveal a significant inverted U-shaped relationship: moderate levels of new entry enhance ESG performance, whereas excessive entry suppresses it due to intensified resource constraints. Mechanism analysis identifies innovation capacity, profitability, and disclosure quality as key transmission channels. Further moderation analysis shows that supply chain resilience and ownership concentration amplify the effects of competitive pressure, while firm age mitigates them. Moreover, new firm entry primarily affects the social dimension of ESG, especially employee compensation. This study enriches the literature on ESG behavior from a competition-based perspective, uncovers the nonlinear dynamics between market competition and sustainable strategy, and offers both theoretical and empirical insights for corporate governance and policy formulation in emerging markets.

Viktor Stojkoski, César A. Hidalgo

Efforts to apply economic complexity to identify diversification opportunities often rely on diagrams comparing the relatedness and complexity or products, technologies, or industries. Yer, the use of these diagrams is not based on empirical or theoretidal evidence supporting some notion of optimality. Here, we introduce an optimization-based framework that identifies diversification opportunities by minimizing a cost function capturing the constraints imposed by an economy's pattern of specialization. We show that the resulting portfolios often differ from those implied by relatedness-complexity diagrams, providing a target-oriented optimization layer to the economic complexity toolkit.

Miguel A. Durán-Olivencia

Bridging the gap between individual agent behavior and macroscopic societal patterns is a central challenge in the social sciences. In this work, we propose a solution to this problem via a kinetic theory formulation. We demonstrate that complex, empirically-observed phenomena, such as the concentration of populations in cities and the emergence of power-law wealth distributions, can be derived directly from a microscopic model of agents governed by underdamped Langevin dynamics. Our multi-scale derivation yields the exact mesoscopic fluctuating (Dean-Kawasaki) dynamics and the macroscopic Vlasov-Fokker-Planck system of equations. The analytical solution of this system reveals how a heterogeneous resource landscape alone is sufficient to generate the coupled structures of spatial and economic inequality, thus providing a formal link between micro-level stochasticity and macro-level deterministic order.

Алла Рябчик

В статті проаналізовано окремі аспекти Інтернет-маркетингу провідних агрохолдингів: Нібулон, Кернел, Миронівський хлібопродукт, Агропросперіс. Встановлено, що в аграрному секторі України Інтернет-маркетинг перебуває на стадії зародження, визначено причини такої ситуації. Також систематизовано і узагальнено найбільш поширені напрями трактування змісту Інтернет-маркетингу, запропоновано авторське визначення. Зазначено бізнес-задачі аграрних підприємств, які можна вирішувати за допомогою Інтернет-маркетингу. Розкрито переваги, можливості, особливості Інтернет-маркетингової діяльності для аграрних підприємств. Дане дослідження носить теоретично-практичний характер: підприємства аграрного сектору зможуть ознайомитися з головними аспектами та складовими Інтернет-маркетингової діяльності, налагодити бізнес-процеси та більш ефективно функціонувати в онлайн бізнес-просторі.

Ievgen Gnitetskyi, Liudmyla Shulhina, Оlena Lymar

The article considers the difference between national cultures and contains a historical overview of the emergence of these differences. The analysis of several historical, natural, social and other factors influencing the behavior of people living in the territory of a certain geographical region has been carried out. A multilevel model of "tightness" and "looseness", which illustrates the connection between factors and parallel processes that arise in society is considered. The core features of each type of cultures are revealed. The relationship between theories of intercultural behavior is revealed, examples of differences among countries are given. An overview of the application of the theory in advertising is given, the perception of deviant behavior in the two types of cultures is explained. The influence of "tightness" and "looseness" on consumers' preferences is analyzed. The specific examples of advertisement of well-known brands are given. Based on the analyzed information, recommendations on the application of the theory in the process of creating advertising messages were developed.

E. M. Kabongo, Ferdinand C. Mukumbang, P. Delobelle et al.

Background Despite the growing global application of mobile health (mHealth) technology in maternal and child health, contextual factors, and mechanisms by which interventional outcomes are generated, have not been subjected to a systematic examination. In this study, we sought to uncover context, mechanisms, and outcome elements of various mHealth interventions based on implementation and evaluation studies to formulate theories or models explicating how mHealth interventions work (or not) both for health care providers and for pregnant women and mothers. Method We undertook a realist synthesis. An electronic search of five online databases (PubMed/Medline, Google Scholar, Scopus, Academic Search Premier and Health Systems Evidence) was performed. Using appropriate Boolean phrases terms and selection procedures, 32 articles were identified. A theory-driven approach, narrative synthesis, was applied to synthesize the data. Thematic content analysis was used to delineate elements of the intervention, including its context, actors, mechanisms, and outcomes. Abduction and retroduction were applied using a realist evaluation heuristic tool to formulate generative theories. Results We formulated two configurational models illustrating how and why mHealth impacts implementation and uptake of maternal and child health care. Implementation-related mechanisms include buy-in from health care providers, perceived support of health care providers’ motivation and perceived ease of use and usefulness. These mechanisms are influenced by adaptive health system conditions including organization, resource availability, policy implementation dynamics, experience with technology, network infrastructure and connectivity. For pregnant women and mothers, mechanisms that trigger mHealth use and consequently uptake of maternal and child health care include perceived satisfaction, motivation and positive psychological support. Information overload was identified as a potential negative mechanism impacting the uptake of maternal and child health care. These mechanisms are influenced by health system conditions, socio-cultural characteristics, socio-economic and demographics characteristics, network infrastructure and connectivity and awareness. Conclusion Models developed in this study provide a detailed understanding of implementation and uptake of mHealth interventions and how and why they impact maternal and child health care in low- and middle-income countries. These models provide a foundation for the ‘white box’ of theory-driven evaluation of mHealth interventions and can improve rollout and implementation where required.

A. I. Terekhov

The purpose of the article is to study the development of research in the field of quantum technologies, based on a bibliometric analysis of publications indexed in databases from the Web of Science Core Collection from 1990 to 2020. The global output of publications, the productivity of individual countries and organizations, indicators of international scientific cooperation are considered. The characteristic features of world studies in the field are revealed: a high concentration in the group of leaders, a noticeable participation of corporations and military scientific structures, and growing international cooperation. Considerable attention is paid to the positions of Russia, which towards the end of the period returned to the top ten countries in terms of productivity. The Russian Academy of Sciences is the sixth among the world scientific organizations in the production of publications on quantum technologies for the entire period; Russian scientists actively cooperate with foreign scientists, including those from leading Western countries. The internal landscape is characterized by a significant predominance of the “Center”, where the country’s leading research institutes and universities are located, and the still small research contribution of the Russian commercial sector.

Raluca-Alexandra Ceocea, Costel Ceocea, Ovidiu-Leonard Turcu et al.

As the COVID-19 pandemic affected the entire world, companies had to develop new techniques and practices to adapt to digital transformation, there came a need for change, for a restructuring of organizational management policy with reference to marketing and communication processes and strategies, organizational procedures, as well as for an awareness of the new technologies that are the bridge towards the online environment. New innovative technologies are the enablers of efficiency and working time reduction, with a focus on automation and systematization. Our aim is to highlight the impact of digitalization on business marketing, the importance of the company’s position and mentality in relation to the current context, as well as the changes in consumer behaviour. The dynamics and fast pace of current trends changes in marketing increase the need to be open about the implementation and adoption of new communication technologies and tools. In this context, organizations must take into account the remodelling of marketing strategies that should be streamlined taking into account intra-organizational and strategic management challenges. Therefore the study aims to outline the implications of digital marketing on the post-pandemic management of companies, and comes up with suggestions related to the allocation of resources in terms of digitalization, that may have a positive impact on improving operational tasks, effectiveness and efficiency through automation.

V. V. Bondarenko, N. A. Nazarova, K. S. Taisheva et al.

One of the key conditions for increasing of Russian education competitiveness in the international market is the active involvement of universities in various international cooperation forms. For this purpose, an analysis of international, federal, local normative legal acts regulating the international activities of Russian higher education institutions was carried out. The international aspect was considered using a comparative legal analysis of agreements between Russia and other countries. The article presents the results of the analysis of the principles of international agreements regulating the educational process in Russian universities. According to the research, a model, regulating the international activities of Russia’s universities, was analysed. The study of regulatory legal acts in Russia’s higher education led to the conclusion about the legislation elaboration level, to outline the prospects for development and the possibility of expanding the domestic universities international activities.

Georgiana-Florina ILIE (POPA), Lucian StANCIU-GORUN

Strongly hit by the pandemic crisis, the hotel industry needs a comeback. After a long period of pandemic, hoteliers are forced to identify new ways to reinvent their business. Many hotels were put up against the wall, taking into account the fact that a serious component of income were the restaurants that were often included in the accommodation package, there was practically the meal supplement. As the return of tourism is still being questioned, hotel representatives need to understand that people need safety and hygiene, which requires increased attention to gain confidence. One way to recover can be Revenue Management strategies adapted to crisis or post-crisis situations. In the following we propose four types of Revenue Management strategies in order to diminish the effects of the pandemic crisis.

Carlos Gracia-Lázaro, Fabio Dercole, Yamir Moreno

Economic unions are international agreements oriented to increase economic efficiency and establishing political and cultural ties between the member countries. Becoming a member of an existing union usually requires the approval of both the candidate and members, while leaving it may require only the unilateral will of the exiting country. There are many examples of accession of states to previously consolidated economic unions, and a recent example of leaving is the withdrawal of the United Kingdom from the European Union. Motivated by the Brexit process, in this paper we propose an agent-based model to study the determinant factors driving withdrawals from an economic union. We show that both Union and local taxes promote the exits, whereas customs fees out of the Union boost cohesion. Furthermore, heterogeneity in both business conditions and wealth distribution promotes withdrawals, while countries' size diversity does not have a significant effect on them. We also deep into the individual causes that lead to dissatisfaction and, ultimately, to exits. We found that, for low Union taxes, the wealth inequality within the country is the leading cause of anti-Union opinion spreading. Conversely, for high Union taxes, the country's performance turns out to be the main driving force, resulting in a risk of wealthier countries leaving the Union. These findings will be helpful for the design of economic policies and effective informative campaigns.

Maxwell Hartt

A. V. Nikitina, O. Shersheniuk, I. Kyrchata et al.

The article analyzes the concepts to determine the essence of the investment project. The theoretical and methodical approach to the definition of an investment project, which will provide the possibility for a clear identification of the essential features, ensure an effective interaction with internal and external dynamic environment is offered. The most common classification features of investment projects are singled out. The main features of the definition of the functions of investment management as a management system and a special area of enterprise management are determined. It was emphasized that for the steady positive development of industrial enterprises in a competitive and rapidly changing environment, effective management of investment activity of enterprises is a necessary condition for functioning. In addition, it is proved that in the context of the limited financial and other types of resources, the use of an integrated approach to investing is one more major area for improving the efficiency of management of investment processes at the macro level, and an integrated investment design is a system-integrated process of management of a set of investment projects that are subordinated to a single strategic plan focused on the successful implementation of the enterprise investment program. The necessity of further, more profound research of investment management in conditions of uncertainty and risk is substantiated. The next stage of the research should be the construction of a system for making investment decisions in conditions of uncertainty and risk.

Henry Nosih Saturwa, Suharno Suharno, Abdul Aziz Ahmad

The Covid-19 pandemic that began to spread at the beginning of 2020 has greatly affected the economy, including firms’ financial conditions. In this respect, micro, small, and medium enterprises (MSMEs) likely experience greater negative effects of the Covid-19 pandemic than large firms due to their limited resources. Hence, this study aims to analyze the impact of Covid-19 on MSMEs’ performance in former Pekalongan Residency, as measured by the sales turnover, labor, and business cash flow resilience. The analysis is based on the survey results of 100 MSMEs in the Pekalongan former regency. The findings suggest that MSMEs have suffered a sales turnover decrease of 1.2573 percent. Further, the mapping analysis using the Cartesian diagram demonstrates that the retail and food and beverage provision sectors exhibit the greatest labor decrease and average business cash flow resilience of 1.5 – 2 months. Meanwhile, based on firm size, micro firms have average cash resilience of 1.5 – 2 months.

David R. Morrison, Washington Taylor

We prove that, for every 6D supergravity theory that has an F-theory description, the property of charge completeness for the connected component of the gauge group (meaning that all charges in the corresponding charge lattice are realized by massive or massless states in the theory) is equivalent to a standard assumption made in F-theory for how geometry encodes the global gauge theory by means of the Mordell-Weil group of the elliptic fibration. This result also holds in 4D F-theory constructions for the parts of the gauge group that come from sections and from 7-branes. We find that in many 6D F-theory models the full charge lattice of the theory is generated by massless charged states; this occurs for each gauge factor where the associated anomaly coefficient satisfies a simple positivity condition. We describe many of the cases where this massless charge sufficiency condition holds, as well as exceptions where the positivity condition fails, and analyze the related global structure of the gauge group and associated Mordell-Weil torsion in explicit F-theory models.

N. T. Dao, J. Dávila, Angela Greulich