Although not a recent tool in the study of elites (Knoke 1994), Social Network Analysis has proven to be a portentous methodology (Higley 2010) in the understanding of these actors. Indeed, it allowed Political Scientists to achieve three major distinctive goals within their work: identifying the structure of those «who rule» (Moore 1979); testing a set of assumptions related to the classic elitist theories (Field and Higley 1980); finally, detecting and analyzing the hidden connections of these elites among themselves or, in a broader context, the connections between these elites and other actors (Galaskiewicz 1989). This said, the use of networks in the empirical study of elites has been mainly undertaken in the context of the five traditional variables underlined by Robert Putnam in his reference study of 1976: sociodemographic profiles, recruitment processes, renovation and circulation, values and beliefs, and structure. This paper seeks to investigate a sixth variable sparsely examined in the field of political elites, the so-called «integrity variables» (Dias Coelho 2012), portraying not only a new set of attributes related to the profile of politicians, but also – and perhaps above all – showing how networks can contribute to a better understanding of «legal» forms of corruption. Based on the analysis of the 2392 Registers of Interests published since 1995 by Portuguese Prime-Ministers, Ministers, Junior Ministers and Members of Parliament, we have developed an hybrid multimethod model which combines Social Network Analysis («Affiliation Networks», «Cluster Analysis») and Prosopography, with the purpose of uncovering hidden networks of power, and thus, unravel hidden overlaps between the political and socioeconomic spheres. In this sense, this new application of networks to the study of elites stands out as a powerful tool in both the understanding of institutional corruption, and the analysis of overlapped interests between the public and the private spheres.
