John Field's Hot Topic paper draws on a diverse literature to assess the relationships between social capital, innovation, sociability and the creation of a learning society.

The Topic contributes to the debate by providing a stock-take of current issues and, refreshingly, by suggesting concrete directions policy makers can take to help build social capital. It advances the widely held view that social capital impacts on our lives in many different ways. However, unlike some popular accounts of the concept, the paper is careful to set out the limits, possibilities, and dangers of building social capital.

One of the paper's key recommendations is that policies should encourage the formation of social networks in the form of clusters and linkages. The justification for this is that clusters and linkages foster innovation. As the arguments goes, competitive advantage is no longer derived from linear models of research and development in which innovative knowledge remained embedded within discipline-based groups.

In the contemporary period, innovation is more likely to emerge from interactions between knowledge generators, firms, investors, and other actors working together in clusters. Hence the claim that social capital is vital to innovation.

While innovation is a social process, as John points out, a major limitation with clusters in terms of equality of opportunity is that they remain closed to outsiders. John explains that one way forward is to develop policies that enable all to participate in networks. Because it provides a means for people a way to gain the skills needed to participate in networks, education has a key role to play in this.

I am less optimistic regarding the potential of education to open networks to outsiders, although it can help. In my view, innovation of a kind that leads to competitive economic advantage, and social inclusion are incompatible. The main reason for this is that positional knowledge, such as that which resides in social networks, loses value once it is shared.

There is an inherent tendency for social closure to develop. Moreover, participating in social networks has always been enhanced by the possession of particular social and cultural behaviours, which are difficult to teach.

However, a key message of this Hot Topic is the need to develop policies that build non-exclusionary forms of social capital. For me, this gives weight to John's argument that we should strive to find ways beyond education to allow outsiders to access insider knowledge.

Rob Strathdee is Senior Lecturer of Education in the School of Education Studies, Victoria University of Wellington, New Zealand, and the author of Social Exclusion and the Remaking of Social Networks, Ashgate, London, 2006.