The Italian Corporate System: SOEs, Private Firms and Institutions in a Network Perspective (1952-1983)

How did business networks among Italian firms evolve over time? We address this question by analyzing the Italian corporate boards network in four years (1952, 1960, 1972, 1983) with network theoretical methods. We find some typical properties of these networks, such as sparsity and connectedness in the same large network component. At the same time, clustering and assortativity are relatively high and stable, while we observe, over time, an increase of the average distance coupled with a decrease of density and of the relative size of the largest component. This is an indication of a rarefaction of connections which is detected also in other national systems. In order to seek the determinants of this phenomenon, we perform a panel regression for the average nodal degree, finding that rarefaction is mostly related to a genuine time trend and only partially to cross-sectional variables. We argue that a possible explanation is a significant increase of concentration which we observe in our dataset, consistently with historical evidence. The network shows a substantial stability in some structures, such as core-periphery subdivision. Looking at the main actors we find a persistent centrality of banks and insurances, as well as of State Owned Enterprises (SOEs). These play a growing role in the community structure of the network, while communities themselves become more and more diversified by sector.