The dynamics of the agent representations and choices interacts with the diffusion dynamics of emitted pollution.
Agents occupy the cells of a two dimensional grid that represent space.
Polluting cars generate pollution at a constant rate s . The s term strongly couples the dynamics of pollution to that of the agents' choices. The range of possible pollution levels correspond to fixed configuration of choices. Pollution is zero when all agents always bought non-polluting cars and maximum and equal to when they all have always bought polluting cars. , the maximum pollution, reflects the cost of pollution, and is the natural scale on which to compare differences in the prior utilities of the agents. However, since the agents only use local information, the gradient of pollution times the range of polling is the relevant parameter to compare differences in prior utilities.