Re-examination of the Convergence in Military Expenditures across NATO Countries: Do Different Approximations in Modelling Structural Breaks Matter?

The goal of this paper is to examine whether the ratio of military expenditures to GDP converges across 27 NATO countries for the period 1993-2018 within the scope of the stochastic convergence analysis. For this purpose, by paying regard to modelling structural breaks, the paper employs unit root tests with and without sharp breaks and also a unit root test with gradual breaks. The empirical findings imply that using different approximations in modelling structural breaks result in different output. The findings indicate weak evidence for the presence of the convergence as well. Theoretical and practical implications of these findings are discussed.