Critical Realism and the Mechanisms of Project Failure in Nigerian Public Sector Capital Projects: A Multi-Case Study

Project failure in Nigerian public sector capital projects is extensively documented but mechanistically underexplained, with most literature remaining at the descriptive level. This study applies critical realism as a philosophical framework to uncover the deep causal mechanisms of project failure in Nigerian public sector capital projects. A retroductive multi-case study design will investigate ten purposively selected failed capital projects across infrastructure, health, and education from four geopolitical zones. Case selection will maximize variation in project type, scale, and geographic zone. Data collection will combine documentary analysis of project files and audit reports, structured interviews with 60 project actors, and process timeline mapping. Critical realist retroduction and retroductive inference will identify underlying generative mechanisms including structural incentive misalignments, institutional capacity deficits, and political economy dynamics. This study provides an original ontologically grounded explanatory framework for Nigerian public project failure, transcending surface-level factor listing to identify the deep structures that produce recurrent failures. Findings will support evidence-based project governance reform. Keywords: critical realism, project failure, public sector, Nigeria, causal mechanisms