Voluntary contribution to public goods in mutual-help forums: reciprocity or group attachment?

This paper studies the provision of public goods in open-source software support forums. Data from the Italian TeX Users Group were analysed to find individual motives for offering help. Using this methodology, we were able to split the forum participants into a small intrinsically motivated core group and a much larger group motivated mainly on the basis of reciprocity. The motives of the two groups were largely complementary and jointly produced a situation where the overwhelming majority of questions received an appropriate answer. At the same time, the core group played a fundamental role and was the key in explaining the forum's success. Without this group, the forum's performance would have been considerably diminished, probably down to a level that would not justify its existence.