Public Expenditure Efficiency and Sustainable Development Outcomes in Sub-Saharan Africa: Evidence from Nigeria and Comparator Economies

The 2030 Agenda for Sustainable Development has intensified global scrutiny of whether
public expenditure generates commensurate progress toward the Sustainable Development
Goals (SDGs). This paper examines the efficiency of public expenditure in producing
SDG-relevant development outcomes — specifically poverty reduction (SDG 1), economic
growth and employment (SDG 8), and infrastructure development (SDG 9) — across Nigeria
and ten structurally comparable Sub-Saharan African economies over the period 2005–2022.
Using a two-stage analytical framework combining Data Envelopment Analysis (DEA) with
Ordinary Least Squares (OLS) regression with HC1 heteroskedasticity-consistent robust
standard errors, we produce bias-corrected government efficiency scores and identify the
institutional and macroeconomic determinants of efficiency variation across the panel. The
DEA model is implemented in Python 3.12 using the HiGHS LP solver (SciPy), with data
drawn from the World Bank World Development Indicators, IMF Government Finance
Statistics, World Bank CPIA database, and the Database of Political Institutions.
Results reveal striking heterogeneity. Kenya, Ghana, and Ethiopia achieve near-frontier
mean efficiency scores of 0.920, consistently converting their expenditure into the maximum
achievable SDG output given sample production possibilities. Nigeria records the lowest
mean efficiency of 0.372 — delivering only 37 per cent of the SDG output its expendi-
ture level should theoretically support. Angola (0.615) and Zambia (0.574) also perform
significantly below the sample mean of 0.758. The Tobit-approximation regression (OLS
with HC1 robust SE, R2 = 0.607) identifies resource revenue dependence (β = −0.0052,
p < 0.001), capital expenditure share (β = 0.0043, p < 0.05), and institutional quality
(β = 0.054, p < 0.10) as the dominant determinants of efficiency variation. Electoral year
effects are negative but statistically insignificant. The findings have direct implications for
fiscal reform, SDG financing design, and the sequencing of public financial management
reforms ahead of the 2030 deadline.