Cargo base or maritime capability? A two-layer index of countries' maritime position, rank uncertainty and a leverage analysis for Türkiye, 2014–2025
Yük tabanı mı, denizcilik yetkinliği mi? Ülkelerin denizcilikteki konumunu iki katmanda ölçen bir endeks, sıra belirsizliği ve Türkiye için kaldıraç analizi, 2014–2025
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Abstract
The goal of becoming a maritime nation is often measured by fleet size or port traffic, yet generating seaborne cargo and being able to carry it are different things. This study proposes a two-layer index that can be computed from open data: a cargo-base index (shares of seaborne trade and container port throughput) and a core maritime capability index (shares of shipbuilding, ownership, flag registration and seafarer supply). Their ratio gives maritime intensity. The index is computed for 238 economies for 2014–2016 and 2023–2025; the sensitivity of the ranking to construction choices is measured with 20,000 simulations, the elasticity of capability with respect to the cargo base is estimated, and the physical equivalent of moving up one rank in each indicator is calculated for Türkiye. Türkiye's cargo-base share rose from 1.15% to 1.40% and its rank from 24th to 20th. Its core capability index, however, fell from 1.14 to 0.98 and its rank from 19th to 22nd; maritime intensity dropped from 1.00 to 0.70. Intensity also declines when seafarer data are excluded. The 5–95% range of Türkiye's rank is 6–25, and 68% of this uncertainty stems from a single choice: whether ship recycling is included in the index. Across countries the elasticity of capability with respect to the cargo base is close to one, but the cargo base explains only about a third (37%) of the variation in capability. Türkiye's weakest link is the flag: if half of the Turkish-owned tonnage under foreign flags returned to the national registry, Türkiye's rank would move from 22nd to 15th on that change alone.
Keywords
Maritime capability; Composite index; Uncertainty analysis; Cargo base; Ship registry; Seafarers; Türkiye
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