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An agent-based computer simulation demonstrates that results from Downs, Duverger, Riker, and Sundquist can be seen as emergent consequences of five simple rules about iteratively forming coalitions and adjusting policy platforms. The model creates distributions of agents who form coalitions within a political body. By modifying and omitting the basic rules, I compare results from plurality and majority-seeking actors and from policy-seeking, office-seeking, and mixed-strategy coalitions. A set of simple rules implemented by agents with extremely bounded knowledge are sufficient to drive the classic median voter, two-party system, minimum winning coalitions, and party realignment results in a single framework. Adapted from the source document.

AbstractWe are entering the third decade of the twenty-first century with profound uncertainties and crucial challenges for the world economy. Phenomena like climate change, digital transformation, migration, demographic changes, and the ongoing COVID pandemic need to be understood and promptly addressed. We argue that the agent-based approach in economics is well suited to tackle these topics, because of its capacity to integrate the "micro" and "macro" dimensions by modelling the network of interactions among heterogeneous economic agents and their aggregate outcomes. This paper explains why the agent-based methodology is needed to overcome the limitations of the neoclassical approach in economics, which has not been able to properly address those challenges. To do so, the paper retraces the main stages of the scientific evolution in a general historical and epistemological perspective, showing how the paradigm of reductionism, which led to extraordinary advances after the scientific revolution of the seventeenth century, is less effective when addressing the main challenges ahead. On the other hand, the sciences of chaos theory and complex systems can provide the economic discipline with more suitable instruments to face those challenges. Finally, the paper briefly presents the contributions of the special issue, which use applications of agent-based models to study the main problems of our times.

The article is devoted to the analysis of existing experience in the application of agent-based approach by modeling migration processes carried out for ongoing development of complex agent-based models to simulate processes in the field of migration policy. Analysis showed that despite the advantages demonstrated by the agent-based approach compared with traditional methods of demographic research simulation reveals various difficulties in terms of simulating migration processes that nevertheless do not underestimate advantages of agent and other existing modeling approaches. Hybrid population-based agent modeling is a new emerging field of study that showed advantages by implementing this approach. The explosive population growth around the world over the past few decades has had an enormous impact on the level of natural resources, the state of the environment and the structure of society in many countries. The study of demographic and migratory trends and the dynamics of changes in the population structure plays a key role in the formation of domestic as well as global policies to achieve sustainable social and environmental development.

Agent-based simulation models have a promising future in the social sciences, from political science to anthropology, economics, and sociology. To realize their full scientific potential, however, these models must address a set of key problems, such as the number of interacting agents and their geometry, network topology, time calibration, phenomenological calibration, structural stability, power laws, and other substantive and methodological issues. This paper discusses and highlights these problems and outlines some solutions.

Transparency is an important factor in democratic societies composed of characteristics such as accessibility, usability, informativeness, understandability and auditability. In this research we focus on auditability since it plays an important role for citizens that need to understand and audit public information. Although auditability has been a subject of discussion when designing systems, there is a lack of systematization in its specification. We propose an approach to systematically add auditability requirements specification during the goal-oriented agent-based Tropos methodology. We used the Transparency Softgoal Interdependency Graph that captures the different facets of transparency while considering their operationalization. An empirical evaluation was conducted through the design and implementation of LawDisTrA system that distributes lawsuits among judges in an appellate court. Experiments included the distribution of over 300,000 lawsuits at the Brazilian Superior Labor Court. We theorize that the presented approach for auditability provides adequate techniques to address the cross-organizational nature of transparency.

As societies face the challenge of securing an efficient and environmentally sound energy supply, researchers have strived to determine the future development of energy consumption, infrastructure and technology endowment. This book proposes a new agent-based approach to studying the development of urban energy systems. Decisions of private and commercial investors and operators are modeled using a bounded rational decision model which are parameterized by socio-economic data. The study goes on to analyze the impact of firms??? competition on technology diffusion and calculate diffusion curves.

Agent-based modeling promises to overcome the reification of actors. Whereas this common, but limiting, assumption makes a lot of sense during periods characterized by stable actor boundaries, other historical junctures, such as the end of the Cold War, exhibit far-reaching and swift transformations of actors' spatial and organizational existence. Moreover, because actors cannot be assumed to remain constant in the long run, analysis of macrohistorical processes virtually always requires "sociational" endogenization. This paper presents a series of computational models, implemented with the software package REPAST, which trace complex macrohistorical transformations of actors be they hierarchically organized as relational networks or as collections of symbolic categories. With respect to the former, dynamic networks featuring emergent compound actors with agent compartments represented in a spatial grid capture organizational domination of the territorial state. In addition, models of "tagged" social processes allows the analyst to show how democratic states predicate their behavior on categorical traits. Finally, categorical schemata that select out politically relevant cultural traits in ethnic landscapes formalize a constructivist notion of national identity in conformance with the qualitative literature on nationalism. This "finite-agent method", representing both states and nations as higher-level structures superimposed on a lower-level grid of primitive agents or cultural traits, avoids reification of agency. Furthermore, it opens the door to explicit analysis of entity processes, such as the integration and disintegration of actors as well as boundary transformations.

There are B2B relationships that presume cooperation in contract enactment. This issue should be taken into account when modeling, for computational handling, contractual commitments through obligations. Deadline obligations have been modeled by considering that reaching the deadline without compliance brings up a violation. When modeling commitments in business contracts, directed obligations have been studied for identifying two agents: the obligation's bearer and the counterparty, who may claim for legal action in case of non-compliance. We argue in favor of a directed deadline obligation approach, taking inspiration on international legislation over trade procedures. Our proposal to model contractual obligations is based on authorizations granted in specific states of an obligation lifecycle model, which we formalize using temporal logic and implement in a rule-based system. The performance of a contractual relationship is supported by a model of flexible deadlines, which allow for further cooperation between autonomous agents. As a result, the decision-making space of agents concerning contractual obligations is enlarged and becomes richer. We discuss the issues that agents should take into account in this extended setting.

After reviewing the main empirical and theoretical findings about the evolution of inequality and its impact on macroeconomic dynamics, this thesis expands the analysis performed with an agent-based model by Napoletano, Roventini and Gaffard (2016). In the model, which is characterized by heterogeneous households with credit constraints, an inequality shock is introduced. This generates a fall in aggregate demand and income. Scenarios with different degrees of inequality are compared, and what emerges is that higher inequality is associated with more severe recessions. Moreover, a redistributive fiscal policy, in the form of a subsidy, is introduced after the crisis. This policy significantly dampens the fall in aggregate output implied by the inequality shock and is more effective than direct government expenditure in stimulating the economy.

Like many developing countries, Nigeria, is faced with a number of tradeoffs that pit rapid economic development against environmental preservation. Environmentally sustainable,"green" economic development is slower, more costly, and more difficult than unrestricted, unregulated economic growth. In this paper we develop an agent-based computational model of agents (who can be individuals or organizations) in a population who make successive choices that have economic and environmental impacts. Simulations based on the model suggest that widespread public awareness of environmental issues is insufficient to prevent the tendency towards sacrificing the environment for the sake of growth. Even if people have an understanding of negative impacts and always choose to act in their own self-interest, they may still act collectively in such a way as to bring down the quality of life for the entire society. We conclude that besides raising public awareness, economic intervention by the government (in the form of incentives or penalties) may be the only way to achieve an optimal balance between economic and environmental factors.

Sovereign default contagion in Eurozone has been under attention since the first problems in Greece at the end of 2009. Despite the improvements in the situation, in particular after several European Central Bank non- conventional monetary policy measures, the roots of the problem and policy prescriptions are still fiercely debated today. Using an agent-based model adapted from Tirole (2015), we simulate sovereign default contagion in a world where countries have random incomes, heterogeneous borrowing behaviors and risk aversion levels and where governments have the possibility to enter in ex-ante agreements to protect against default. We conclude that default contagion can be a very fast and 'destructive' process, higher spending countries tend to have lower disposable incomes and higher risk aversion levels are associated with lower default rates. ; info:eu-repo/semantics/publishedVersion