Economic sanctions are usually measured in goods: exports blocked, cargoes seized, customs flows redirected. A maritime service economy feels them somewhere else. Freight earnings arrive through the services account of the balance of payments, as transport receipts, and those receipts can move with a sanctions regime even when the country’s own customs data show nothing unusual.
Greece is the natural place to test this. Its fleet is among the largest in the world while the domestic economy is small, so shipping income is a material share of the external account, and the sector earns most of that income on routes between third countries. Polemis and Likas, in a 2026 study in Case Studies on Transport Policy, use this setting to ask whether sanctions intensity still moves with Greek transport receipts after controlling for world trade, oil prices, exchange rates, sovereign risk and the freight cycle.
The design stays entirely on public data. Transport receipts come from the Bank of Greece balance of payments at monthly frequency. Sanctions intensity comes from the fourth release of the Global Sanctions Database, which codes episodes by sender, target and instrument, and the sample is restricted to 2003 to 2023 to match that database’s coverage, 251 monthly observations in all. The freight cycle enters through the Dallas Fed’s index of global real economic activity, with the Baltic Dry Index and an Aframax tanker-rate series used on shorter overlapping samples.
The central finding is an asymmetry between regimes. In the preferred model the Iran-related EU sanctions index enters log transport receipts at minus 0.141, while the Russia-related EU/G7 index enters at plus 0.432. Translated into levels, a full move of each index from zero to one corresponds to receipts roughly 13.1 percent lower under the Iran measure and 54.0 percent higher under the Russia measure. A more modest 0.1 step in either index maps to about 1.4 percent lower and 4.4 percent higher receipts respectively.
An obvious objection is that sanctions episodes coincide with freight-market swings, and that the receipts are simply tracking the cycle. The study addresses this head on. Adding the global-activity index attenuates both coefficients and leaves the signs intact. Reconstructing the dependent variable with Eurostat sea-transport and sea-freight shares preserves the pattern, as do the shorter models that control for the Baltic Dry Index and Aframax rates. Six-month lead terms are insignificant, which weighs against reverse timing, and lagged sanctions terms keep the expected signs.
The authors are equally open about the limits. Year-on-year growth models fail to reproduce the coefficients. A dynamic specification with a lagged dependent variable preserves the positive Russia term and washes out the Iran term. The estimates are therefore presented as conditional associations in the level of receipts, with no claim to a causal treatment effect, and monthly aggregates cannot see individual vessels, cargo decisions or compliance choices.
The asymmetry has a coherent economic reading. An Iran-type regime hits Greek earnings through direct exposure: cargoes disappear, insurance and class cover are withdrawn, payment channels close, and the affected trades shrink. A Russia-type regime, imposed on a counterpart embedded throughout seaborne energy and bulk flows, redirects trade across the network. Voyages lengthen as cargoes find more distant buyers, route substitution absorbs tonnage, and the freight balance tightens. Service receipts can rise through that channel even where every vessel involved is fully compliant.
Balance-of-payments data record the net of these two mechanisms and nothing finer. The authors read the positive Russia coefficient as the signature of a fleet adjusting to a redrawn trade map, and they caution against treating it as evidence of evasion by Greek owners. The trade-diversion literature they draw on documents the same logic in many settings: sanctions redirect flows through third countries and alternative routes as often as they suppress them.
The study also carries the question into the domestic banking system. Russia-related intensity is positively associated with twelve-month changes in corporate loan rates, at a coefficient of 3.676, and with the loan-deposit spread, at 1.692; the Iran index is positive in the spread model as well, at 0.673. The authors keep these models secondary. The samples are shorter, the series are aggregates, and the results support conclusions about credit pricing and intermediation margins while establishing nothing about systemic transmission. The implied supervisory watchlist is specific: concentrated shipping borrowers, collateral values, trade finance and payment screening.
For an owner or principal the practical content is in how exposure is assessed. Sanctions risk is regime-specific. A regime aimed at a counterpart with limited network weight cuts income through the withdrawal of cargoes, cover and payments. A regime aimed at a counterpart central to energy and bulk flows can lift service income across the market while raising the compliance and monitoring burden that comes with it. Treating sanctions as a single category of risk misses that distinction, and the difference between minus 13 percent and plus 54 percent in the Greek record is a measure of how much it can matter.
There is also a measurement lesson in the paper’s treatment of offshore jurisdictions. Greek exposure calculated without offshore centres still trends upward, so the pattern is more than an artefact of corporate structuring, and offshore registration remains ordinary practice in international shipping. The paper argues for separating ordinary corporate architecture from genuine opacity channels, a distinction that monitoring frameworks built on customs data alone are poorly placed to make.
The external validity is bounded and stated. The findings travel to maritime service economies and shipping-finance hubs where transport receipts are a material external-account item, and they say little about large diversified economies. Within that scope the Greek record from 2003 to 2023 supports a plain expectation: when a major sanctions regime arrives, the first place it shows up for a shipping economy is the services ledger, and the direction of the move depends on which trades the measures touch.