Agent-Based Modelling

A boardroom simulation is only useful if you know what was being simulated. That sounds obvious. It is also where many AI-agent demos quietly fall apart. Give one hundred language-model agents a set of personas, drop them into a toy market, forum, election, auction, or customer-support queue, and the result will usually look interesting. Someone panics. Someone coordinates. Someone overpays. Someone posts something faintly unhinged. Excellent. We have recreated the internet. ...

TL;DR for operators Cities rarely wait for perfect data. A new district still needs a transit plan, a campus still needs a shuttle model, and a developer still wants to know whether people will walk, drive, or quietly defeat the entire urban-design deck by ordering a car. The paper behind this article introduces Preference Chain, a method that uses a small sample of behavioural mobility data to guide an LLM agent’s transport choices.1 The important bit is not that it “adds Graph RAG” to an LLM. That phrase now covers everything from serious retrieval systems to someone throwing a Neo4j logo onto a slide. The real mechanism is narrower and more useful: Preference Chain turns sparse human travel records into structured priors over likely choices, then lets the LLM adjust those priors for context. ...

TL;DR for operators Simulation is a dangerous place to confuse optimisation with truth. Chen and Zhang’s paper, From Individual Learning to Market Equilibrium, shows that a reinforcement learning agent can optimise very successfully and still fail to reproduce the economic equilibrium it was supposedly simulating.1 That is the useful sting in the paper. The failure is not that the RL agent is too weak. The failure is that the environment quietly gives the agent the wrong economic role. ...