The model’s primary aim was not to be entirely realistic; instead, it was designed to point to new questions, test the usefulness of the tool, and lay the groundwork for new insights. As such, this model is targeted at ecologists, ornithologists, and urban planners who want to test and simulate how different birds face the challenge of a densely urbanized city that aims to enhance its natural connectivity and foster a wide range of biodiversity. We aimed to identify bird movement at the city-wide scale, encompassing representatives from the entire avian community, while examining differences in movement between totally random models and an informed model, defined by expert criteria.

This study separates operational interoperability, fare integration and revenue-sharing governance in a stylised multi-operator bus network. An agent-based model implemented in NetLogo 7.0.3 represents passengers, buses and stations across 14 stations, nine routes and three operators. A 2 × 2 institutional design is complemented by financial clearing comparisons and 43,200 robustness runs: behavioural sensitivity (E1), a 243-configuration operational factorial (E2), and targeted joint behavioural–operational stress testing (E3). The audited experiment records show favourable interoperability effects on waiting, total travel time, transfers and realised generalised cost in all 1,944 E2 and 768 E3 configuration-level primary comparisons. Fare integration substantially reduces passenger expenditure but produces an aggregate deficit under the assumed accounting coefficients. Revenue-sharing rules redistribute operator-level outcomes without changing aggregate profit or passenger trajectories by construction. The model is intended to identify mechanisms and test conditional robustness, not predict city-specific policy effects. The paper contributes an explicit separation of access, pricing and settlement mechanisms coupled with reproducible factorial and stress-test comparisons.

An agent-based model to explore human–wild boar interactions in urban and suburban landscapes at the interface with agricultural land and natural habitats, by simulating wild boar population growth, mortality, and movements across the landscape

This NetLogo model simulates the movement and foraging behavior of 20 bird species (classified as urban avoiders or utilizers) across a 20×20m grid landscape representing southern Bogotá, Colombia. Agents follow an optimal foraging strategy (90% of the time) or move randomly (10%), gaining energy from land-cover-dependent food sources and dying if energy falls below their basal metabolic rate. The model compares two landscape scenarios — current land cover (2016) and a proposed scenario incorporating the ‘Media Luna del Sur’ ecological corridor from Bogotá’s 2022–2035 Land Use Plan (POT) — to evaluate whether the proposed green infrastructure improves functional connectivity for avian biodiversity across the urban matrix. Outputs include cumulative patch visitation counts, exported as raster files, used to generate connectivity heatmaps.

Diversity has become a defining feature of most Western societies, where boundaries of membership extend beyond ethnicity to encompass multiple intersecting categories, increasing the complexity of social integration. The aim of this model is to adapt the classical Schelling model of spatial segregation to this context and to identify mechanisms that may generate the hybrid segregation patterns where individuals are segregated from out-groups along one dimension while remaining integrated along others.

We extend the Schelling model using a discrete choice framework that incorporates dominant and secondary preferences among agents from two ethnic groups. Liberal agents prioritize cross-ethnic shared values over ethnicity, whereas conservative agents prioritize ethnic membership over shared values, although both retain some preference for the secondary dimension. The model is designed to explore how heterogeneous preferences and intersecting group memberships interact under different group compositions and initial distributions.

An agent-based model of how public space conditions shape the collective formation of local sports communities in high-mobility cities. A small gathering is already exercising in an abstract, systematically configurable public space; the model asks how strangers join them and whether the loose gathering consolidates into a stable community. Three conditions are manipulated, each acting through exactly one channel: spatial legibility governs whether a passer-by notices the activity, routine compatibility governs whether a member attends in a given week, and social anchor availability governs how much one episode of co-presence builds a tie. Ties carry a continuous strength with two thresholds, so that relationships of differing strength cross their thresholds at different condition levels. Because the model does not represent the origin of an activity, dissolution is irreversible and survival is a clean binary outcome. Across 32,790 runs in eight experiments the model yields two well separated thresholds along routine compatibility — one for survival, one for consolidation — with a wide band between them in which a space is used continuously but no community forms. The tie submodel is adapted from Jin, Girvan and Newman (2001) and verified against it by docking. Robustness is established against the seeded gathering, the pre-existing social network, a joint ±20 per cent perturbation of the behavioural parameters, and the parameters of the tie machinery.

This model tests whether local housing supply elasticity governs crash severity inside a single metropolitan housing market. Saiz (2010) established that across US metros, regions constrained by geography and regulation experience deeper boom-bust cycles than flexible ones. That finding is routinely applied downward to neighborhoods and ZIP codes as though the mechanism scaled without qualification.

The empirical record for the Washington DC and Northern Virginia region says it does not. Across 84 ZIP codes, measured supply elasticity ranges from 0.35 to 4.95 with a median of 1.21. The worst single-year price decline between 2007 and 2012 averaged 9.6 percent in constrained ZIP codes and 9.0 percent in flexible ones, a gap that cannot be distinguished from noise. Wide variation in the proposed cause, no meaningful separation in the proposed effect.

The model embeds households, houses and a metro-wide credit condition in the real ZIP geography of the region using three GIS layers and an empirical price panel. Local elasticity governs construction, exactly as theory predicts. Prices are driven by a shared macro drift schedule and, under the credit-amplified mode, by a leverage cycle with a financial accelerator and a deviation penalty. The design question is whether those shared forces are sufficient to override local supply differences at the sub-metropolitan scale.

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An integrated wildfire and urban growth model for informal settlements.

Fire-WCISG is developed to test the impact of different fire management strategies on the number and type of residents staying in an informal settlement, and the fire-dependent fynbos vegetation that it is next to.

The model uses a hybrid protection motivation theory, place attachment and Turner’s informal residents as described by Christ et al. (2023) (10.1016/j.habitatint.2023.102815), for the agents decision making. Wildland vegetation is based on published understanding of fynbos ecology.

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This paper develops a spatial agent-based model to examine how fertility regime shifts reshape population concentration and wealth distribution in an abstract urban system. Migration decisions combine population preference, cultural homophily, expected net income, and resource endowment through a standardised softmax utility. The design is deliberately stylised: it is not calibrated to a particular country or city system, but is intended to isolate the feedbacks linking migration, fertility, urban scaling, and accumulated wealth.
The simulations reveal robust directional asymmetry. When fertility shifts from low to high, population concentration responds rapidly; when fertility shifts from high to low, concentration declines only after a detectable delay and may temporarily continue in the previous direction. Wealth adds a second layer of hysteresis: cell total-wealth concentration follows population concentration with delay, cell mean-wealth inequality and system-level wealth indicators are slower still, and phase-space trajectories form loops rather than collapsing onto a single population–wealth curve. Robustness experiments indicate that longer fertility cycles, wider mobility neighbourhoods, and smoother resource landscapes change the magnitude of delay and overshoot, but do not remove the qualitative asymmetry. The paper argues that demographic decline should be understood not as the mirror image of demographic expansion, but as a path-dependent transition mediated by fast migration-income feedbacks and slower fertility, cohort, culture, and wealth mechanisms.

This model is an extension of Wilensky’s (2003) Traffic Grid, a foundational NetLogo model of urban traffic flow. It embeds a dual-process cognitive architecture into each driver agent, transforming the original’s identical reactive units into cognitively heterogeneous individuals whose internal mental state evolves with experience; making the same intersection produce different decisions from different drivers, and different decisions from the same driver across occasions.
The core question the model addresses is the yellow-light dilemma zone: the seconds following amber onset in which a driver can neither stop safely nor clear the intersection before red. Field research documents that behavioral variance at this moment cannot be explained by geometry or legal obligation alone. This model provides the cognitive architecture that has been missing from traffic ABMs.
Each driver routes every amber-onset decision through either System 1 (fast, heuristic, automatic) or System 2 (slow, deliberative, prospect-theoretic), switching dynamically based on cognitive load, accumulated near-miss memory, and situational framing. The result is crash outcomes that are attributable, path-dependent, and sensitive to both driver disposition and signal infrastructure; none of which fixed-rule models can reproduce. Three signal control modes are included: fixed-cycle (replicating Wilensky’s original), adaptive-queue, and smart occupancy-based switching.