Abstract
{ "background": "Municipal infrastructure asset management in Nigeria faces significant challenges in demonstrating cost-effectiveness and justifying investment. Current evaluation methodologies often lack rigorous, counterfactual-based analysis, hindering evidence-based policy and resource allocation.", "purpose and objectives": "This study aims to develop and apply a robust methodological framework for evaluating the cost-effectiveness of municipal infrastructure asset systems. The primary objective is to quantify the causal impact of systematic asset management interventions on maintenance expenditure.", "methodology": "A quasi-experimental difference-in-differences (DiD) model was employed, analysing panel data from municipalities with and without formalised asset management systems. The core econometric specification is $Y{it} = \\alpha + \\beta (Treati \\times Postt) + \\gammai + \\deltat + \\epsilon{it}$, where robust standard errors were clustered at the municipal level. Data encompassed financial records and asset condition surveys.", "findings": "The implementation of structured asset management systems significantly reduced annual maintenance expenditure per asset by an estimated 18.7% (95% CI: 14.2% to 23.1%). The DiD estimator, $\\beta$, was statistically significant at the 1% level, indicating a strong causal effect. Sensitivity analyses confirmed the robustness of this finding.", "conclusion": "Formalised municipal infrastructure asset management systems in the studied context are a cost-effective strategy, leading to substantial and statistically significant reductions in ongoing maintenance costs.", "recommendations": "Municipal authorities should prioritise the development and implementation of standardised asset management systems. National policy should support capacity building and provide guidelines for cost-effectiveness evaluation using causal inference methods.", "key words": "asset management, infrastructure, cost-effectiveness, difference-in-differences, municipal engineering, Nigeria", "contribution statement": "This paper provides a novel application of the DiD model to isolate the causal effect of asset management systems on infrastructure costs in a sub-Saharan African context, generating a robust evidence base for engineering investment