A Comprehensive Meta-Analysis of Determinants Influencing Military Expenditure: New Methodological Insights and Implications for Defence Budget Allocation

The aim of this article is to conduct a meta-analysis of existing research on the determinants of military expenditure. Using data from an initial screening of 179 studies, 15 studies were selected for meta-analysis, contributing 20,023 observations to analyze key variables influencing defense budget allocations. By employing a random-effects meta-analysis, this study synthesizes findings across diverse geopolitical and economic contexts, addressing inconsistencies in prior research and enhancing the reliability of conclusions. Our findings indicate that war, current military expenditure, and the presence of external threats (enemies) are significant drivers of military spending, while national conditions show a significant negative correlation with military expenditure. Other variables, including GDP, population, democracy, trade, FDI, arms exports, alliances, threats, and political regime type, do not show strong correlations. By combining data from multiple studies, this methodological approach not only generalizes results and improves the precision of effect estimates but also identifies gaps to guide future defense economics research. This research provides policymakers with a broader understanding of the factors shaping defense budgets, offering insights into how traditional budgeting methods might be complemented by a data-driven approach.