Using Social Network Analysis to Unveil Cartels in Public Bids

In recent years, the study of complex networks has attracted great attention. Several fields of science have used techniques of social network analysis and complex networks to represent a wide range of structures such as; social networks, political influence, communication, epidemics and several other aspects of human behavior. Most of the complex networks show community structures. Revealing these communities is highly relevant to understanding several social phenomena such as the organizing of groups, the flow of information and the strength of the influence of some members over the group. In this article, we use techniques of social network analysis and complex networks to represent the relationship between companies that are participating in public bids to unveil community structures analog to cartels. Several nations are facing injuries trough the misuse of public money caused by the formation of cartels, which are groupings of companies aiming to defraud the free competition. Our main goal in this work is to present a methodology for identifying these communities. Furthermore, we aim to address wheter companies that have high success rates in public bids are grouped and identify whether they are taking advantage of their influence in the network.