Environmental issues are characterised by uncertainty and problems of coope
ration. Societal responses to such challenges are institutions: beliefs, no
rms, relationships, property rights, agencies, etc. We discuss here a botto
m-up approach to the emergence of institutions such as beliefs and norms in
pollution issues and agri-environmental policy implementation. The models
are based on networks of automata, Bayesian updating and coupled map lattic
es. They exhibit clear organisational properties and regime transitions acc
ording to their parameters. The behaviours predicted by these models often
differ from the predictions of standard economy based on unbounded rational
ity. (C) 2000 Elsevier Science B.V. All rights reserved.