MARKET CONCENTRATION AND NETWORK-BASED DEPENDENCY IN TÜRKIYE’S FERTILIZER IMPORTS: AN ANALYSIS OF NITROGEN, PHOSPHATE, AND POTASH TRADE

Öz

This study empirically analyzes the evolution of supplier concentration and structural dependence in Türkiye’s imports of nitrogenous (HS 3102), phosphatic (HS 3103), and potassic (HS 3104) fertilizers from 2004 to 2023. Using annual bilateral trade data, the study applies a dual methodological framework that combines traditional scalar measures, including the Herfindahl-Hirschman Index (HHI), Entropy Index (EI), and concentration ratios (CR), with complex network analysis metrics to assess supply chain vulnerability. The findings reveal a clear structural divide across product groups. While the nitrogenous fertilizer market underwent a temporary phase of diversification between 2009 and 2016 before reconcentration, the phosphatic and potassic sectors maintained persistently high oligopolistic concentration levels throughout the study period. Network analysis corroborates these scalar indicators, identifying Türkiye as a peripheral, demand-side actor characterized by marked single-sourcing risks in phosphate and potash trade, in contrast to its relatively well-connected importer position linked to core suppliers in the nitrogen network. The study concludes that the high level of import concentration observed in these critical inputs creates significant supply security risks by exposing agricultural input markets to geopolitical and economic shocks. These results underscore the need for policy measures that prioritize supplier diversification and integrate resilience criteria into national food security strategies.

Anahtar Kelimeler

• Fertilizer
• Market Concentration
• Herfindahl–Hirschman Index
• Entropy Index
• Network Analysis

Etik Beyan

I declare that the study does not require ethics committee permission.

TÜRKİYE’NİN GÜBRE İTHALATINDA PAZAR YOĞUNLAŞMASI VE AĞ TABANLI BAĞIMLILIK: AZOT, FOSFAT VE POTAS TİCARETİ ANALİZİ

Öz

Bu çalışma, Türkiye’nin azotlu (HS 3102), fosfatlı (HS 3103) ve potasyumlu (HS 3104) gübre ithalatında tedarikçi yoğunlaşması ve yapısal bağımlılığın 2004–2023 dönemindeki gelişimini ampirik olarak analiz etmektedir. Yıllık ikili ticaret verilerinden yararlanılan çalışmada, tedarik zinciri kırılganlığını değerlendirmek amacıyla Herfindahl–Hirschman Endeksi (HHI), Entropi Endeksi (EI) ve yoğunlaşma oranları (CR) gibi geleneksel ölçütler ile kompleks ağ analizi metriklerini bir araya getiren ikili bir yöntemsel çerçeve kullanılmıştır. Bulgular, ürün grupları arasında belirgin bir yapısal farklılaşma olduğunu ortaya koymaktadır. Azotlu gübre piyasasında 2009–2016 döneminde geçici bir çeşitlenme süreci yaşanmış, ancak sonrasında yeniden yoğunlaşma eğilimi görülmüştür. Buna karşılık fosfatlı ve potasyumlu gübrelerde çalışma dönemi boyunca sürekli yüksek ve oligopolistik yoğunlaşma düzeyleri gözlenmiştir. Ağ analizi bulguları da bu yoğunlaşma göstergelerini desteklemekte; Türkiye’nin fosfat ve potasyum ticaretinde belirgin tek tedarikçiye bağımlılık riski taşıyan çevresel ve talep yönlü bir aktör olduğunu, azotlu gübre ağında ise çekirdek tedarikçilerle bağlantılı görece daha iyi bağlantılanmış bir ithalatçı konumunda bulunduğunu göstermektedir. Çalışma, söz konusu kritik girdilerde gözlenen yüksek ithalat yoğunlaşmasının, tarımsal girdi piyasalarını jeopolitik ve ekonomik şoklara açık hâle getirerek önemli arz güvenliği riskleri oluşturduğu sonucuna ulaşmaktadır. Bu bulgular, tedarikçi çeşitlendirmesini önceleyen ve dayanıklılık kriterlerini ulusal gıda güvenliği stratejilerine entegre eden politika önlemlerine ihtiyaç duyulduğunu göstermektedir.

Anahtar Kelimeler

• Gübre
• Pazar Yoğunlaşması
• Herfindahl–Hirschman Endeksi
• Entropi Endeksi
• Ağ Analizi

Etik Beyan

Bu çalışmanın etik kurul onayına gerek duymadığını beyan ederim.

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