The emergence of an ever-widening sphere of global public policy is a new reality in a world characterized by the blurring of boundaries between the national and the global; by flows of ideas, people, and commodities; and by new global risks and opportunities. In this context, this article explores the empirical puzzle of the sudden outbreak of reforms leading to central-bank independence. How can we best understand the outbreak of reforms in the 1990s? It is suggested here that the reforms were diffused in a contagious and uncoordinated manner in a global policy process that may best be captured by Kingdon's policy stream model. We develop an agent-based model to evaluate the effects of three little-explored aspects of the diffusion process. These are (i) the likelihood of the outbreak of reform, (ii) the rate of adoption of the reform, and (iii) the time to outbreak. We find that the likelihood of outbreak depends on the saliency of a problem, in conjunction with the length of time that a problem has been on the public agenda. We also find that an increase in the size of the environment surveyed before a decision is made increases the rate of adoption but also the time to outbreak. The more global the information available for agents, the longer is the time to outbreak, but outbreaks unfold much faster.
This research note provides a general introduction to REsCape: an agent-based computational framework for studying the relationship between natural resources, ethnicity, and civil war. By permitting the user to specify: (i) different resource profiles ranging from a purely agrarian economy to one based on the artisanal or industrial extraction of alluvial or kimberlite diamonds; (ii) different patterns of ethnic domination, ethnic polarization, and varying degrees of ethnic salience; as well as (iii) specific modes of play for key agents, the framework can be used to assess the effects of key variables - whether taken in isolation or in various combinations - on the onset and duration of civil war. Our objective is to make REsCape available as an open source toolkit in the future, one that can be used, modified, and refined by students and scholars of civil war.
Explanations of the emergence of regional autonomy movements - political organizations seeking to express sub-state affinities and interests - often highlight cultural differences and economic incentives as important reasons driving regional elites and local politicians to form such organization and explain the support regional autonomy movements receive. In this paper I employ a specialized agent-based computer simulation as a laboratory for `thought experiments' to evaluate alternative theoretical expectations of the independent and combined consequences of regional economic and cultural circumstances on the likelihood of regional mobilization. The simulations suggest that pronounced cultural differences and strong economic incentives contribute to the emergence of three independent yet related aspects of autonomy mobilization: the emergence of political boundaries, minority support, and minority clustering. Furthermore, these experiment indicate that the impact of cultural differences on the emergence of political boundaries may be contingent on the strength of the economic incentives, and visa versa.
Institutional frameworks powerfully determine the goals, violence, and trajectories of identitarian movements-including secessionist movements. However, both small-N and large-N researchers disagree on the question of whether ``power-sharing'' arrangements, instead of repression, are more or less likely to mitigate threats of secessionist mobilizations by disaffected, regionally concentrated minority groups. The PS-I modeling platform was used to create a virtual country ``Beita,'' containing within it a disaffected, partially controlled, regionally concentrated minority. Drawing on constructivist identity theory to determine behaviors by individual agents in Beita, the most popular theoretical positions on this issue were tested. Data were drawn from batches of hundreds of Beita histories produced under rigorous experimental conditions. The results lend support to sophisticated interpretations of the effects of repression vs. responsive or representative types of power-sharing. Although in the short run repression works to suppress ethnopolitical mobilization, it does not effectively reduce the threat of secession. Power-sharing can be more effective, but it also tends to encourage larger minority identitarian movements.
Constructivist approaches to the emergence and stability of collective identities are now widely accepted. But few of the assumptions of constructivist theory regarding repertoires of identities and their mutability in response to changing circumstances have been examined or even articulated. The article shows how different conditions of a fluid and changing environment affect the stabilization or institutionalization of an identity as dominant within a polity. We used the Agent-Based Identity-Repertoire (ABIR) model as a simulation tool and confined out, attention to relatively simple identity situations. Strong evidence was found for the emergence of identity institutionalization, the existence of a ``crystallization'' threshold, the effectiveness of divide-and-rule strategies for the maintenance of an identity as dominant, the efficacy of a network of organic intellectuals, and hegemonic levels of institutionalization. Thresholds leading to hegemony were not observed. Preliminary results from experiments examining more complex identity situations have been corroborative.
This study uses the Agent-Based Identity Repertoire model to investigate the ability of populations to adapt and learn in an unpredictable environment. The authors' findings highlight the trade-off between adaptation and diversity in the pursuit of performance but also show that this trade-off is far from straightforward Increasing sophistication improves the ability to adapt but reduces diversity, imposing high costs down the line. However, high levels of sophistication also produce small, stable homogeneous clusters of agents, which slow down declines in diversity. Innovative or entrepreneurial agents reacting more rapidly to environmental signals increase the prevalence of such clusters, helping diversity but hampering adaptability. The authors also show that more predictable environments facilitate successful adaptation, especially for populations of intermediate sophistication. Finally, the authors conclude that the trade-off between adaptation and diversity is such that in the present model, long-term learning is difficult to achieve.
Agent-based modeling is a technique used to study relationships between variation in parameter values or patterns of interaction at the micro-level and outcomes at the macro-level. By using computer simulation of landscapes inhabited by cells, or “agents,” the modeler can produce many virtual histories of the landscape under different initial conditions (randomized or not) and under various experimental conditions. In this article we report the findings of experiments run with the Agent-Based Argument Repertoire (ABAR) Model—experiments designed to help answer some of the practical questions that arise in discussions of the contribution-enhanced public discourse, that is, more and better deliberation or argumentation among citizens might contribute to the quality of democracy.