In this paper we assess the suitability of weighted-indexed semi-Markov chains (WISMC) to study risk measures as applied to high-frequency financial data. The considered measures are the drawdown of fixed level, the time to crash, the speed of crash, the recovery time and the speed of recovery; they provide valuable information in portfolio management and in the selection of investments. The results

Classical language dynamics explain language shift as a process in which speakers adopt a higher status language in lieu of a lower status language. This is well documented with English having out-competed languages such as Scottish Gaelic, Welsh, and Mandarin. The 1961–1991 Indian censuses report a sharper increase in Hindi/English Bilinguals compared to Monolingual Hindi speakers, suggesting that

COVID-19 confronts societies and individuals with unprecedented challenges. It is advocated that complex systems theory, in general, and synergetics, in particular, provide a valuable and comprehensive repertoire of tools and concepts such as the concept of amplitude equations and order parameters to study the spread of COVID-19 in human populations. Specifically, within the framework of SIR and SEIR

Systems design utilizes top-down and bottom-up approaches to influence social or economic systems such that a desired outcome is obtained. We characterize different approaches like network controllability, network interventions, nudging and mechanism design and discuss the problems involved. We argue that systems design cannot be reduced to solving complex optimization problems.

Tax credit management system (TCMS) implemented by the State Administration of Taxation (SAT) of China in 2014 is an innovative mechanism of tax collection and management. This paper attempts to incorporate the TCMS into the model of Allingham and Sandmo [Allingham, M. G. and Sandmo, A., Income tax evasion: A theoretical analysis, J. Public Econ.1(3–4) (1972) 323–338], and then proposes an agent-based

In our multi-agent model, agents generate wealth from repeated interactions for which a prisoner’s dilemma payoff matrix is assumed. Their gains are taxed by a government at a rate α. The resulting budget is spent to cover administrative costs and to pay a bonus to cooperative agents, which can be identified correctly only with a probability p. Agents decide at each time step to choose either cooperation

What makes Question & Answer (Q&A) communities productive? In this paper, we look into how the diversity of behavioral types of agents impacts the performance of Q&A communities using different performance metrics. We do this by developing an agent-based model informed by insights from previous studies on Q&A communities. By analyzing the different strategies for how questions are selected to answer

In science and especially in economics, agent-based modeling has become a widely used modeling approach. These models are often formulated as a large system of difference equations. In this study, we discuss two aspects, numerical modeling and the probabilistic description for two agent-based computational economic market models: the Levy–Levy–Solomon model and the Franke–Westerhoff model. We derive

We consider a honeybee colony as a dynamical system gathering information from an environment and accordingly adjusting its behavior. Collective foraging behavior is shown to be triggered by the change of either colony size or profitability of exploited nectar sources. The collective mode provides greater productivity compared to the individual one. The latter does not diminish the importance of individual

The central subject of this paper is the relation between the macro-level of the Society and the micro-level of its individuals. In complex real-life systems, this relationship is not trivial and even the result at the macro-level can be counter-intuitive. One of the first models that highlights this is the Sakoda and Schelling’s model of spatial segregation where a person uses a selfish rule to decide

This study examines the information flow between prices and transaction volumes in the cryptocurrency market, where transfer entropy is used for measurement. We selected four cryptocurrencies (Bitcoin, Ethereum, Litecoin and XRP) with large market values, and Bitcoin and BCH (Bitcoin Cash) for hard fork analysis; a hard fork is when a single cryptocurrency splits in two. By examining the real price

We present an extended version of the Iterated Prisoner’s Dilemma game in which agents with limited memory receive recommendations about the unknown opponents to decide whether to play with. Since agents can receive more than one recommendation about the same opponent, they have to evaluate the recommendations according to their disposition such as optimist, pessimist, or realist. They keep their first

A complex network is an explicit model for a real-world system such as technological networks, social networks, business networks, and biological networks. The social network is an Internet-based media for socially relevant activities like stay connected with families and friends, colleagues, and customers, for socializing, business, or both. The key nodes, usually called central nodes, capable of

In this work, spreading of information is investigated in a vehicular ad hoc network (VANET) by agent-based simulation. The proposed model is complex, containing two major states and some minor substates and additionally both reversible and irreversible state changes. According to our results, the spreading is really fast and widespread, the system can be in an up-to-date phase without external control

Sovereign default contagion was one of the most debated topics during the Eurozone sovereign debt crisis. Despite all the improvements in the financial situation since 2010, namely after European Central Bank quantitative easing policies, the nature of the problem and the policy prescriptions are still under dispute today. Using an agent-based model, we simulate sovereign default contagion for different

Traffic assignment is an important stage in the task of modeling a transportation system. Several methods for solving the traffic assignment problem (TAP) were proposed, mostly based on iterative procedures. However, little was done in the direction of analyzing the difficulty of such procedures. For instance, why is it that some networks require orders of magnitude more iterations than others? What

We propose a model of the speech perception of individual words in the presence of mishearings. This phenomenological approach is based on concepts used in linguistics, and provides a formalism that is universal across languages. We put forward an efficient two-parameter form for the word length distribution, and introduce a simple representation of mishearings, which we use in our subsequent modeling

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst.21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input

Since the 1970s, scholars have begun to pay attention to the presentation of women in Bede’s Ecclesiastical History of the English People, the main source for the early history of Britain (from the first century BC to the eighth century AD). Vastly different conclusions have been drawn, ranging from positivist approaches which saw the period as a golden age for women to rather more negative assessments

This paper considers patterns of organization in distributions of the rate of return on capital (RoC) realized by individual enterprises. It shows that large-sample cross sections of RoC across several European economies are persistently well described by the same functional form: Sharply peaked distributions with stretched-exponential tails. To account for this observation, the paper develops a systemic

While wealth distribution in the world is highly skewed and heavy-tailed, human talent — as the majority of individual features — is normally distributed. In a recent computational study by Pluchino et al. [Talent vs luck: The role of randomness in success and failure, Adv. Complex Syst. 21(03–04) (2018) 1850014], it has been shown that the combined effects of both random external factors (lucky and

At a mixed Nash equilibrium, the payoff of a player does not depend on her own action, as long as her opponent sticks to his. In a periodic strategy, a concept developed in a previous paper [V. K. Oikonomou and J. Jost, Periodic strategies: A new solution concept and an algorithm for nontrivial strategic form games, Adv. Compl. Syst. 20(5) (2017) 1750009], in contrast, the own payoff does not depend

A cellular automaton model called the Firm Dynamics Model (FDM) is introduced to simulate the dynamics of firms within an economy. The model includes the growth of firms and their mergers and exits...

Recent theoretical studies on network robustness have focused primarily on attacks by random selection and global vision, but numerous real-life networks suffer from proximity-based breakdown. Here...

Our ability to understand and control the emergence of order in swarming systems is a fundamental challenge in contemporary science. The standard Vicsek model (SVM) — a minimal model for swarming s...

Network science has experienced unprecedented rapid development in the past two decades. The network perspective has also been widely applied to explore various complex systems in great depth. In t...

Minimal edge controllability of directed networks is investigated in this paper. A new edge dynamics model is first introduced with two nonzero parameters describing the linear relationship between...

We propose a new measure to quantify the impact of a node $i$ in controlling a directed network. This measure, called `control contribution' $\mathcal{C}_{i}$, combines the probability for node $i$ to appear in a set of driver nodes and the probability for other nodes to be controlled by $i$. To calculate $\mathcal{C}_{i}$, we propose an optimization method based on random samples of minimum sets of

To promote the implementation of realistic control over various complex networks, recent work has been focusing on analyzing energy cost. Indeed, the energy cost quantifies how much effort is required to drive the system from one state to another when it is fully controllable. A fully controllable system means that the system can be driven by external inputs from any initial state to any final state

The ability to steer the state of a dynamical network towards a desired state within a time horizon is intrinsically dependent on the number of driven nodes considered, as well as the network’s top...

Boolean models represent a drastic simplification of complex biomolecular systems, and yet accurately predict system properties, e.g., effective control strategies. Why is this? Parameter robustnes...

Large complex dynamical systems behave in ways that reflect their structure. There are many applications where we need to control these systems by bringing them from their current state to a desire...

In this paper, we propose a self-organization mechanism for newly appeared nodes during the formation of corona graphs that define a hierarchical pattern in the resulting corona graphs and we call ...

We present results of network analysis of Ukrainian texts. Autosemantic (meaningful) words are considered as network vertices connected with links when belonging to one sentence. Subnetworks corres...

Today, there exist many centrality measures for assessing the importance of nodes in a network as a function of their position and the underlying topology. One class of such measures builds on eigenvector centrality, where the importance of a node is derived from the importance of its neighboring nodes. For directed and weighted complex networks, where the nodes can carry some intrinsic property value

This paper is based on the premise that economic growth is driven by an interplay between innovation and imitation in an economy composed of interacting firms operating in a stochastic environment. A novel approach to modeling imitation is presented, based on range-dependent processes that describe how firms consider proximity when imitating peers who are found in a given neighborhood in terms of productivity

Based on the stability theory of fractional-order systems, a projective synchronization scheme with different coefficients is realized in 1+N complex networks to build a model for fractal pattern recognition. In the proposed complex function projection synchronization scheme, first a drive-response network is constructed with 1+N fractional-order complex nodes; And then reasonable controllers are designed

Cellular automaton models of complex systems (CSs) are gaining greater popularity; simultaneously, they have proven the capability to solve real scientific and engineering applications. To enable everybody a quick penetration into the core of this type of modeling, three real applications of cellular automaton models, including selected open source software codes, are studied: laser dynamics, dynamic

This work has been partially supported by the Ministerio de Economia y Competitividad grant MTM2017-89664-P and by the European Union through the Operational Program of the European Regional Development Fund (ERDF)/European Social Fund (ESF) of the Valencian Community 2014-2020, grants GJIDI/2018/A/009 and GJIDI/2018/A/010.

We assume a community whose members adopt one of two opinions. Each member appears as an inflexible, or as a non-contrarian or contrarian floater. An inflexible adheres to its opinion, whereas a floater may change into a floater of the alternative opinion. The occurrence of this change is governed by the local majority rule: members meet in groups of a fixed size, and a floater changes provided its

In this paper, we consider a system in which knowledge in a dispersed form is available. In the system local classifiers are combined into coalitions. Two methods of combining classifiers in coalit...

A community is the basic component structure of complex networks and is important for network analysis. In recent decades, researchers from different fields have witnessed a boom of community detec...

Recent advances in data collection and storage have allowed both researchers and industry alike to collect data in real time. Much of this data comes in the form of 'events', or timestamped interactions, such as email and social media posts, website clickstreams, or protein-protein interactions. This of type data poses new challenges for modelling, especially if we wish to preserve all temporal features

Humanity has been fascinated by the pursuit of fortune since time immemorial, and many successful outcomes benefit from strokes of luck. But success is subject to complexity, uncertainty, and change - and at times becoming increasingly unequally distributed. This leads to tension and confusion over to what extent people actually get what they deserve (i.e., fairness/meritocracy). Moreover, in many

We consider the fraction of nodes that default in large, stochastic, inhomogeneous financial networks following an initial shock to the system. Results for deterministic sequences of networks are g...

Options framework is one of the prominent models serving as a basis to improve learning speed by means of temporal abstractions. An option is mainly composed of three elements: initiation set, opti...

The impact of cybermediaries’ information on Consumer to Consumer (C2C) tax compliance is investigated by using a computational experiment approach and three conclusions are drawn. First, cybermedi...

Stochastic volatility models describe asset prices St as driven by an unobserved process capturing the random dynamics of volatility σt. We quantify how much information about σt can be inferred fr...

Economic complexity measures have been constructed on the basis of bipartite country-product network data, but without paying attention to the technological dimension or manufacturing capabilities. In this study, we submit a Ternary Complexity Index (TCI), which explicitly incorporates technological knowledge as a third dimension, measured in terms of patents. Different from a complexity indicator

An analytical framework for the analysis of multi-hump solitons is proposed in this paper. Multi-hump solitons are defined by imposing special symmetry conditions on the classical soliton expression. Such soliton solutions have a wide range of potential applications in the field of optical communications. The proposed algebras of soliton solutions enable a new look at the propagation dynamics of complex

In order to unveil the value of network connectivity, discounted both in space and time, we formalize the construction of networks as an optimal control dynamic graph-theoretic problem. The network...

We introduce a method to infer lead-lag networks of agents’ actions in complex systems. These networks open the way to both microscopic and macroscopic states prediction in such systems. We apply t...

This paper establishes a trade credit network with a guarantee mechanism. Based on the established network model, the trade credit network and the guarantee network are visualized. The characterist...

In the last decade, the economic community has been characterized by a growing debate on the methods used in research. In particular, the financial crisis exposed the mainstream general equilibrium models used by economists to their flaws and drawbacks (Fagiolo and Roventini, 2017) and also policymakers claimed to feel ''abandoned'' by the conventional tools (Trichet, 2010). The weaknesses of conducting

We consider a simple model of agents modifying their opinion about themselves and about the others during random pair interactions. Two unexpected patterns emerge: (1) without gossips, starting from zero, agents’ opinions tend to grow and stabilize on average at a positive value; (2) when introducing gossips, this pattern is inverted; the opinions tend to decrease and stabilize on average at a negative

In Schelling’s segregation model, agents of two ethnic groups reside in a regular grid and aim to live in a neighborhood that matches the minimum desired fraction of members of the same ethnicity. The model shows that observed segregation can emerge from people interacting under spatial constraints following homophily preferences. Even mild preferences can generate high degrees of segregation at the

Given a system where the real-valued states of the agents are aggregated by a function to a real-valued state of the entire system, we are interested in the influence or importance of different agents for that function. This generalizes the notion of power indices for binary voting systems to decisions over interval policy spaces and has applications in economics, engineering, security analysis, and

Rumor spreading is a good sample of spreading in which human beings are the main players in the spreading process. Therefore, in order to have a more realistic model of rumor spreading on online social networks, the influence of psycho-sociological factors particularly those which affect users’ reactions toward rumor/anti-rumor should be considered. To this aim, we present a new model that considers

Social issues are generally discussed by highly-involved and less-involved people to build social norms defining what has to be thought and done about them. As self-involved agents share different attitude dynamics to other agents [Wood, W., Pool, G., Leck, K. and Purvis, D., Self-definition, defensive processing, and influence: The normative impact of majority and minority groups, J. Pers. Soc. Psychol

The advantages of groups over individuals in complex decision-making have long interested scientists across disciplinary divisions. Averaging over a collection of individual judgments proves a reli ...