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Journals / Uluslararası Ekonomi Siyaset İnsan ve Toplum Bilimleri Dergisi / 2026 / Cilt: 9 Sayı: 3 Özel Sayı

Convergence of Defence Expenditure in Eastern Mediterranean and Middle East Countries Towards The United States: Evidence From Wavelet-Based ADF and Fourier ADF Analyses

Doğu Akdeniz ve Orta Doğu Ülkelerinde Savunma Harcamalarının ABD’ye Yakınsaması: Wavelet Tabanlı ADF ve Fourier ADF Analizlerinden Kanıtlar

Murat Aykırı(KAFKAS ÜNİVERSİTESİ)0000-0002-0108-8839
Kerem Karabulut(ATATÜRK ÜNİVERSİTESİ)0000-0002-3159-3289
Pages
1–19
Publication Date
2026-07-01
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AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

This finding for Turkey and Saudi Arabia reveals that defence policies in the region are relatively coordinated in the short and medium term but become more divergent in the long term, reflecting country-specific strategic preferences.

📌 3 Key Takeaways

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Objective & Hypothesis:This study examines the convergence dynamics of the defence expenditure burdens (military expenditure/GDP) of Turkey, Israel, Greece, Iran, Egypt and Saudi Arabia, located in the Eastern Mediterranean and Middle East, relative to the United States, which is considered the global leader.
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Key Findings & Data:Using SIPRI data for the period 1965–2024, difference series for the defence burdens of the relevant countries relative to the US were created within the framework of Bernard and Durlauf's stochastic convergence definition, and classical ADF unit root tests were first applied to these series.
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Conclusion & Impact:This finding for Turkey and Saudi Arabia reveals that defence policies in the region are relatively coordinated in the short and medium term but become more divergent in the long term, reflecting country-specific strategic preferences.
🔬Design:Araştırma Makalesi
📍Scope:2024 Verileri
⚙️Variables:Yakınsama Hipotezi · Askeri Harcama Yükü · Wavelet Analizi

Abstract

This study examines the convergence dynamics of the defence expenditure burdens (military expenditure/GDP) of Turkey, Israel, Greece, Iran, Egypt and Saudi Arabia, located in the Eastern Mediterranean and Middle East, relative to the United States, which is considered the global leader. Using SIPRI data for the period 1965–2024, difference series for the defence burdens of the relevant countries relative to the US were created within the framework of Bernard and Durlauf's stochastic convergence definition, and classical ADF unit root tests were first applied to these series. Subsequently, the structural break sensitivity of the results was controlled using the Fourier ADF (FADF) test, which internalises multiple structural breaks and non-linear trends. The original contribution of the study is the separation of defence expenditure differences into short, medium and long-term components using MODWT-based wavelet decomposition and the re-execution of ADF and FADF tests for each frequency band. Thus, the convergence hypothesis was analysed not only in terms of a ‘yes/no’ dichotomy but also in a time-horizon-sensitive manner. Empirical findings show that in the short term, all countries in the sample exhibited stochastic convergence towards the US; in the medium term, convergence partially strengthened; and in the long term, convergence towards the US persisted only for Israel, Greece, Iran, and Egypt. Turkey and Saudi Arabia, however, diverge from other countries in the long term. This finding for Turkey and Saudi Arabia reveals that defence policies in the region are relatively coordinated in the short and medium term but become more divergent in the long term, reflecting country-specific strategic preferences.

Özet

Bu çalışma, Doğu Akdeniz ve Orta Doğu’da yer alan Türkiye, İsrail, Yunanistan, İran, Mısır ve Suudi Arabistan’ın savunma harcaması yüklerinin (askeri harcamalar/GSYH) küresel lider ülke olarak kabul edilen ABD’ye göre yakınsama dinamiklerini incelemektedir. 1965–2024 dönemine ait SIPRI verileri kullanılarak, Bernard ve Durlauf’un stokastik yakınsama tanımı çerçevesinde ilgili ülkelere ait savunma yüklerinin ABD’ye göre fark serileri oluşturulmuş ve bu seriler üzerinde öncelikle klasik ADF birim kök testleri uygulanmıştır. Daha sonra, çoklu yapısal kırılmaları ve doğrusal olmayan eğilimleri içselleştiren Fourier ADF (FADF) testi ile sonuçların yapısal kırılma duyarlılığı kontrol edilmiştir. Çalışmanın özgün katkısı, MODWT tabanlı Wavelet (Dalgacık) ayrıştırması kullanılarak savunma yükü farklarının kısa, orta ve uzun dönem bileşenlerine ayrılması ve her frekans bandı için ADF ve FADF testlerinin yeniden yürütülmesidir. Böylece, yakınsama hipotezi yalnızca “var/yok” ikiliği üzerinden değil, zaman ufkuna duyarlı bir biçimde analiz edilmiştir. Ampirik bulgular, kısa dönemde örnekleme dâhil tüm ülkelerin ABD’ye doğru stokastik yakınsama sergilediğini, orta dönemde yakınsamanın kısmen güçlendiğini, uzun dönemde ise sadece İsrail, Yunanistan, İran ve Mısır için ABD’ye yakınsamanın sürdüğünü göstermektedir. Türkiye ile Suudi Arabistan ise uzun dönemde diğer ülkelerden ayrışmaktadır. Türkiye ve Suudi Arabistan için elde edilen bu sonuç bölgedeki savunma politikalarının kısa ve orta vadede görece eşgüdümlü, uzun vadede ise daha ayrışan ve ülke bazlı stratejik tercihleri yansıtan bir yapı taşıdığını ortaya koymaktadır.

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Cite This Article

Aykırı, M., Karabulut, K. (2026). Convergence of Defence Expenditure in Eastern Mediterranean and Middle East Countries Towards The United States: Evidence From Wavelet-Based ADF and Fourier ADF Analyses. Uluslararası Ekonomi Siyaset İnsan ve Toplum Bilimleri Dergisi, Cilt: 9 Sayı: 3 Özel Sayı, 1–19. https://doi.org/10.59445/ijephss.1919731

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