THE USE OF NETWORK ANALYSIS FOR THE DETECTION OF CORRUPTION IN PUBLIC PROCUREMENT: THE BULGARIAN CASE AS A TESTING GROUND

Abstract

This article uses Bulgaria as a case study to explore the application of network analysis to detect corruption in public procurement. Based on procurement data from 2016 to 2022, the study constructs bipartite graphs to analyze patterns of supplier concentration, single-tender tendering, and network stability across political cycles. The findings reveal persistent high-risk sectors - such as construction, medical supplies, and fuels - characterized by closed supplier networks and limited competition. While general network structures remain stable under changes in government, the disappearance of specific high-profile nodes suggests politically driven market reconfigurations. These results demonstrate the potential of network analysis as a policy tool to enhance anticorruption efforts.