The IMP group's ARA model, with its emphasis on interaction, captures social and economic dimensions of exchanges. We draw on it to compare three cases and assess how actors act in skilful and nuanced ways in mobilizing resources, given the very different norms of social and economic capital. We prioritize action ahead of structure and, given the inherent uncertainties that actors encounter in connection with resources, argue that trust is a cognitive and heuristic dimension of action, distinct from resources, actor-bonds and social capital. We conclude that for business practice, managers should be mindful that in order to trust others, they need to act in the distinct realms of social and economic capital, tempting though it is to interpret and measure the costs of actions economically. (c) 2010 Elsevier Inc. All rights reserved.