Modern technical solutions are characterized by an increased interrela
tedness between heterogeneous actors and knowledge fields. No single f
irm can keep pace with the development of all relevant technologies. T
herefore, firms must have access to external knowledge sources. Inform
al networks or cooperative environments are an organizational device f
or external learning. In the paper the master-equation approach is app
lied to model the evolution of an informal network. Using this method
we can totally dispense with the rigorous assumption of perfect ration
ality that is usually employed when modelling cooperative behaviour. O
ur results show that under a regime where technology is of major impor
tance, know-how sharing and the emergence of informal networks is poss
ible via self-organization (C) 1997 Elsevier Science Ltd.