This paper uses the 1698 Slavonian census to illuminate features of social organization and productive activity of an eastern European population under the New Feudalism of the 17th century. In particular we investigate the ability of community or kinship networks to provide substitutes for missing markets in securities and production factors. It is found that kinship networks increase the efficiency of agricultural production by facilitating the exchange of oxen. This confirms contemporary reports that draft animals were the critical constraint to the expansion of agricultural output. We also find that kinship networks fail to reduce the variability of output through mutual harvest insurance.