Assessment of the Impact of Corruption on Construction Project Delivery in the Public Sector in Nigeria

Corruption in construction procurement and project management is widely recognised as a major impediment to public infrastructure delivery in Nigeria, yet its specific impacts on project performance metrics are under-quantified in professional literature. This study assessed the impacts of corruption on construction project delivery in the Nigerian public sector through a nationwide survey of construction professionals in all six geopolitical zones. Structured questionnaires were administered to 180 professionals (quantity surveyors, project managers, engineers, and contractors) with public sector project experience. Corruption manifestations assessed included contract inflation, bribery in procurement, kickbacks for variation approval, and certification fraud. The Relative Importance Index was used to rank corruption impacts. Respondents' estimates of the financial magnitude of corruption in their project experience were aggregated. Results showed that contract sum inflation (padding) was the most important corruption form (RII = 0.91), followed by bribery in contractor shortlisting (RII = 0.87) and kickbacks for variation orders (RII = 0.83). Respondents estimated that corruption inflated average public building project costs by 25 to 40% above honest market prices. Completion time was extended by a mean of 38% in projects where procurement corruption was reported. The study concludes that corruption is a systemic and severe impediment to public construction project delivery in Nigeria, and recommends strengthened Independent Corrupt Practices Commission oversight of construction procurement, open contracting data publication, and protected whistleblower mechanisms.

Keywords: corruption, public sector construction, project delivery, procurement, Nigeria