Abstract: Collaboration is a fundamental aspect of social and economic life. Collaborations are conceptualized as productive exchanges that improve the welfare of all participants involved. But, on the downside, productive exchange can also result in social exclusion. In this paper we address theoretically how and under what conditions social exclusion arises in in knowledge-intensive collaboration, modeled as productive exchange between strategically interacting individuals. We show which network configurations are likely to emerge when actors can choose with whom to collaborate and whom to leave out of their exchanges. A key innovation of our model is the distinction of two types of expertise in knowledge intensive production, generalist and specialist expertise.  We show how heterogeneity in expertise can breed inequality and social exclusion in productive exchanges. Our model implies that actors’ incentives to form more or less collaborations depend on their individual expertise. The more generalists there are, the more projects are formed but the less resources are invested in each. And, if actors are free to rearrange their connections if a more profitable option is available, there will be segregation between types of expertise. The specialists exclude the generalists from the exchange even though generalists are interested in collaborating with them. Therefore, those who need collaboration the most to be optimally productive are least likely to be included into collaborative exchanges.