Calibrating complex agent-based models shouldn't mean settling for a single "best guess" parameter set. Kejian Li presents a new HPC-ABC-SMC framework that cuts #ABM calibration time by 42x while capturing complete parameter uncertainty. Watch here👉 youtu.be/SQ8hzmVj2gQ

Calibrating a Global Trade Agent-Based Model with an HPC–ABC–SMC Framework

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Single-point estimates are not enough for complex #ABM calibration. A new framework delivers full #BayesianComputation posterior distributions with a 42-fold efficiency gain, applied to a global #FoodTrade model. Read the full #OA article in #JASSS: jasss.org/29/3/5.html

The same voting reform can polarize one democracy and moderate another. It comes down to system size. Thomas Mustillo (@keoughglobalnd.bsky.social, @kellogginstitute.bsky.social) breaks down his new #JASSS paper on party competition under costly voting🎥 youtu.be/lWkAIoc_hIE

Party Competition with Costly Voting

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Abstainers live at the extremes, not the centre. A new #ABM shows that voting costs reshape entire #PartySystem dynamics, driving #polarization in small party systems while eroding citizen representation in larger ones Read the full #OA article in #JASSS: jasss.org/29/3/4.html

Why is it so hard to stop eating #UltraProcessedFoods? The simple truth is that dieting alone will not do it. A new #ABM study shows that only drastically reducing UPF availability can reverse learned food preferences. Read the full #OA article in #JASSS: jasss.org/29/3/3.html

Where does inequality come from, before states, markets, or agriculture? New #ABM reveals how stratification emerges in hunter-gatherer societies, driven by skill, luck, greed, and what a society chooses to reward. Full #OpenAccess article in #JASSS 👉https://www.jasss.org/29/3/2.html

System-level interventions can ignite cascades of change. They can also collapse under mis-targeting. New #JASSS paper models the tradeoff and proposes a portfolio approach to scale power without losing the safety net. Read #OpenAccess here: www.jasss.org/29/3/1.html

📢 #JASSS Issue 3 (Vol. 29) is out. How does order, inequality, and change emerge from individual decisions? From behavioral policy to ancient societies to global trade — this issue explores it all through agent-based modeling. Read here 👇 www.jasss.org/JASSS.html

🔎 Sneak peek from the forthcoming #JASSS issue: #Nudge individuals, or reshape the systems around them? Wrong question. Author shows it's a transformation–robustness tradeoff 👇 www.youtube.com/watch?v=4eY_... #ABM #BehavioralScience #PublicPolicy

S-Frame Vs. I-Frame Interventions: The Transformation-Robustness Trade-off in Behavioural Policy

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Who is most at risk in aged care facilities, and when? A new #ABM study builds institutional #ContactMatrices from staff shifts and care routines, revealing where #InfectiousDisease transmission truly concentrates. Read the full #OA article in #JASSS: jasss.org/29/2/7.html

Not all nodes are equal — yet #Network models treat them as if they were. A new study adapts the Configuration Model to embed node attributes into #NetworkStructure, with a tenfold increase in #ClusteringCoefficient. Read the full #OA article in #JASSS: jasss.org/29/2/6.html

More realistic #AgentBasedModels are not always better: a new study shows that richer agent #Heterogeneity undermines #ModelCalibration reliability — reopening the KISS vs KIDS debate on new empirical ground. Read the full #OpenAccess article in #JASSS: jasss.org/29/2/5.html

No protests in the streets — yet resistance grows. A new #ABM study models how #OnlineProtest dynamics on #SocialMedia quietly accumulate dissent potential among ordinary users even under #AuthoritarianRepression. Read the full #OA article in #JASSS: jasss.org/29/2/4.html

Bad news travels fast — but how exactly? A new #ABM study combines #DeepLearning sentiment tracking and an epidemiological model to map how negativity about corporations spreads across Reddit's #FinancialCommunities. Read the full #OA article in #JASSS: jasss.org/29/2/3.html

What drives households to adopt rooftop #SolarPV? A new #ABM study reveals that it is not just money —#socialnorms and #opiniondynamics matter more, with surprising insensitivity to #network structure. Read the full #OpenAccess article in #JASSS: jasss.org/29/2/2.html

No algorithms, no biased media, no hostile users — yet #polarization still emerges. A new #ABM study extending Axelrod's model shows how rewarding interactions alone fuel a self-reinforcing "rich-get-richer" dynamic. Read the full #OA article in #JASSS: jasss.org/29/2/1.html

#JASSS Vol.29 Issue 2 is out! New research explores online polarization, authoritarian repression, solar PV adoption & financial sentiment spread, and more — all through the lens of #AgentBasedModeling. Find out what #ComputationalSocialScience reveals about society 👉 jasss.org

Can #socialsolidarity prevent agro-pastoral collapse? Paul Chapron & colleagues co-designed an #ABM with Senegalese farmers to find out. ⚠️Spoiler: remove parcel lending & food sharing, and the system collapses #CompanionModeling #participatory #simulation youtu.be/gucSiwhHqW0

Fallow Land Simulations to Fight Soil Degradation: Engaging Stakeholders with Model Exploration

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Real-world #Policy problems are hard to capture with traditional models, but a #generative approach may change the game. GPLab combines #LLMs and #ABM to advance #computationalsocialscience for public decision support. Read the full #OA article in #JASSS: jasss.org/29/1/6.html

How long before #OpioidPolicy actually reduces deaths? OPOSim #ABM simulates #OpioidUse dynamics in #NorthCarolina to test #prevention strategies and reveals how small shifts can change #epidemic trajectories Read the full #OpenAccess article in #JASSS: jasss.org/29/1/5.html

Can #AI safeguard a healthy #InfoEcosystem? An #ABM simulation shows that proactive #Bots outperform reactive #FactChecking in mitigating the spread of #ConspiracyTheories on #SocialMedia. Read the full #OpenAccess article in #JASSS: jasss.org/29/1/4.html

How do you #model what can’t be measured? This study demonstrates how #ParticipatoryModeling integrates local knowledge and #Calibration to capture hidden social dynamics in complex socio-ecological systems. Read the full #OpenAccess article in #JASSS: www.jasss.org/29/1/3.html

Why do non-political issues polarize? This #MultiAgentModel with #NetworkHomophily solves the discrepancy between #Simulation and #Empirical findings, showing that #OilSpillPolarization can emerge even among moderate partisans. Read the full #OpenAccess article in #JASSS: www.jasss.org/29/1/1.html

The first #JASSS issue of 2026 has been published! Dive into new #SocialSimulation studies on #PublicPolicy, #Epidemiology, #SoilDegradation, and #OpinionDynamics. Read the full #OpenAccess articles in Vol 29(1) here: www.jasss.org/29/1/content...

The #JASSS website just got a major upgrade! 🚀 We have launched brand new dedicated sections for Awards, News, and Videos to highlight the main updates and amazing work happening in our community. Come see what’s new! 💻 www.jasss.org/JASSS.html

#ABM thrives but fragmented code and reinvented wheels slow progress. We introduce #AGENTBLOCKS, an open #community #platform that shares & improves #ReusableBuildingBlocks to support #Standardization in ABM and beyond. Read the full #OpenAccess article in #JASSS: www.jasss.org/28/4/11.html

Structural calibration of ABMs is often overlooked, yet it can dramatically shape model outcomes. We address this by introducing an innovative #InverseModelling #method to #explore & #calibrate #ABM #structures Read the full #OpenAccess article in #JASSS: www.jasss.org/28/4/10.html

Who should be traced first? An empirically calibrated #ABM shows that #ContactTracing works best when prioritizing influential spreaders—even if identified only via simple proxies like #Age and #HouseholdSize. Read the full #OpenAccess article in #JASSS: www.jasss.org/28/4/9.html

By fitting an #ABM of #schoolchoice to household-level data, this study reveals unexpected #heuristic #behaviors shaping #SchoolSegregation dynamics and offers a novel #estimation #framework for realistic ABMs. Read the full #OpenAccess article in #jasss: jasss.org/28/4/8.html

How do #PaymentForPerformance reshape care-seeking? An #ABM of childbirth care in #Tanzania links provider incentives, informal fees, peer learning, and demand pressure, revealing effects of supply-side change. Read the full #OpenAccess article in #jasss: jasss.org/28/4/7.html