This model implements a coupled opinion-mobility agent-based framework in NetLogo, extending Attraction-Repulsion Model (ARM) dynamics with endogenous migration in continuous 2D space.

Each agent has an opinion s in [0,1] and a spatial position (x,y). Agents interact locally within an interaction radius, with exposure-controlled interaction probability. Opinion updates follow ARM rules: attraction for small opinion distance and repulsion for large distance (tolerance threshold T). After social interaction, agents move according to a social-force mechanism that balances attraction to similar neighbors and avoidance of dissimilar neighbors, controlled by orientation bias (approaching goods vs leaving bads). The model also includes an optional exposure-mobility coupling setting.

Main outputs include polarization (P), spatial assortativity (Moran’s I), mixed-neighbor fraction (f_mix), and good-component count (N_g). The model is designed to study phase behavior of polarization and segregation under mobility and tolerance heterogeneity.

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In his 2003 book, Historical Dynamics (ch. 4), Turchin describes and briefly analyzes a spatial ABM of his metaethnic frontier theory, which is essentially a formalization of a theory by Ibn Khaldun in the 14th century. In the model, polities compete with neighboring polities and can absorb them into an empire. Groups possess “asabiya”, a measure of social solidarity and a sense of shared purpose. Regions that share borders with other groups will have increased asabiya do to salient us vs. them competition. High asabiya enhances the ability to grow, work together, and hence wage war on neighboring groups and assimilate them into an empire. The larger the frontier, the higher the empire’s asabiya.
As an empire expands, (1) increased access to resources drives further growth; (2) internal conflict decreases asabiya among those who live far from the frontier; and (3) expanded size of the frontier decreases ability to wage war along all frontiers. When an empire’s asabiya decreases too much, it collapses.  Another group with more compelling asabiya eventually helps establish a new empire.

This model simulates a forest ecosystem affected by human logging. We explore different kind of approaches and their possible consequences for the ecosystem. Loggers can either be responsible or irresponsible, they will either take care to cut trees or not. In turn their actions will have consequences on the quality of the soil, the atmosphere as well as their profit made from logging. In this model we see that even careful management cannot prevent the degradation of the forest ecosystem.

This agent-based model, developed for the study “Online Protest and Repression in Authoritarian Settings,” examines how online protest and repression evolve in authoritarian contexts and how these dynamics affect ordinary users’ attitudes and behavior on social media. The model integrates key theoretical and empirical insights into social media use and core political factors that shape digital contention in authoritarian settings. The following questions are addressed: (1) how online protest–repression dynamics unfold across different levels of authoritarianism and varying compositions of committed accounts, and (2) how ordinary users’ internal propensity to protest and their perceived probability of successful repression change during online protest-repression contestation. The model is evaluated against two empirically grounded macro patterns observed in the real world. The first is enduring protest: online protest becomes dominant as vocal protesters grow to outnumber vocal repressors, shrinking the pool of silent users and stabilizing a pro-protest majority. The second is suppressed protest: online dissent is contained as vocal repression and silence expand in response to protest, yielding a sustained majority of repressive and silent accounts. Together, these dynamics demonstrate how dissenting voices are empowered and suppressed online in authoritarian settings.

Boyds (Boids that Fight) is an agent-based model in NetLogo that extends the classic Flocking model with multi-faction competition, a local fight–flight heuristic, and a target locking/“taking” mechanism. The model separates perception (vision) from engagement range (lock distance) and uses per-faction steering bounds to explore how local numerical superiority, sensing, and bounded turning affect victory, losses, and emergent formations.

Software for an agent-based game-theoretic model of the contact hypothesis of prejudice reduction, to accompany “Modeling Prejudice Reduction,” in the Handbook of Computational Social Psychology, adapted from Public Affairs Quarterly 19 (2) 2005.

NOMAD is an agent-based model of firm location choice between two aggregate regions (“near” and “off”) under logistics uncertainty. Firms occupy sites characterised by attractiveness and logistics risk, earn a risk-adjusted payoff that depends on regional costs (wages plus congestion) and an individual risk-tolerance trait, and update location choices using aspiration-based satisficing rules with switching frictions. Logistics risk evolves endogenously on occupied sites through a region-specific absorption mechanism (good/bad events that reduce/increase risk), while congestion feeds back into regional costs via regional shares and local crowding. Runs stop endogenously once the near-region share becomes quasi-stable after burn-in, and the model records time series and quasi-stable outcomes such as near/off composition, switching intensity, costs, average risk, and average risk tolerance.

The model examines cattle herd dynamics on a patchy grassland subject to two exogenous pressures: periodic raiding events that remove animals and scheduled management culling that can target males and/or females. It is intended for comparative experiments on how raiding frequency, culling schedules, vegetation dynamics, and life-history parameters interact to shape herd persistence. The model was specifically designed to test the scenario of cattle herding in the arid grasslands of southern Arizona and northern Sonora during the mission period (late 17th through late 18th centuries, CE). In this period, herds were locally managed by Spanish mission personnel and local O’odham groups. Herds were culled mostly for local consumption of meat, hides, and tallow, but the mission herds were often targets for raiding by neighboring groups. The main purpose of the model is to examine herd dynamics in a seasonally variable, arid environment where herds are subject to both intentional internal harvest (culling) and external harvest (raiding).

This agent-based model simulates how new immigrant households choose where to live in Metro Vancouver under the origins diversity scenario. The model begins with 16,000 household agents, reflecting an expected annual population increase of about 42,500 people based on an average household size of 2.56. Each agent is assigned four characteristics: one of ten origin categories, income level (adjusted using NOC data and recent immigrant earnings), likelihood of having children, and preferred mode of commuting. The ten origin groups are drawn from Census patterns, including six subgroups within the broader Asian category (China, India, the Philippines, Iran, South Korea, and Other Asian countries) and two categories for immigrants from the Americas. This refined classification better captures the diversity of newcomers arriving in the region.

This model explores the coupled dynamics of social norm diffusion and finite resource depletion. Extending the “Affordance Landscape” framework by Kaaronen & Strelkovskii (2020), this simulation investigates how resource scarcity and regeneration rates influence the adoption of pro-environmental behaviours.

The model addresses the gap by linking behavioural norms to a depleting common-pool resource. It tests whether sustainable norms can diffuse rapidly enough to prevent ecological collapse and identifies “tipping points” where resource scarcity acts as a driver for behavioural change.