Consumer adoption in the light of beliefs diffusion: an agent-based approach

This paper introduces G-Impact, an agent-based model that combines modelling of household consumption and belief diffusion. Household decisions integrate personal impacts (quality, cost), perceived consequences (climate change, human responsibility), and social norms. The evaluation of these different criteria relies on household beliefs, which can be exchanged during social interactions. These beliefs can be used to explain household decisions on a macro and micro scale, and thus to target information or incentive policies. The model is applied to dietary choice in France, among the omnivorous (INCA3), the flexitarian and the vegetarian diets. The costs and greenhouse gases emissions of the different diets are initialized from real data, initial beliefs of households are derived from opinion surveys.We observe after 5 years of simulation a significant increase in the proportion of flexitarians, and a slight increase in the proportion of vegetarians. We use the model to design an information campaign in the aim of making INCA3 dieters switch to the flexitarian diet, and analyse its impact.