A Refreshed Taxonomy to Monitor Non-Tariff Measures

US tariff policy is reshaping trade policy worldwide. Keeping pace demands fine distinctions across tariffs and non-tariff measures. Our previous taxonomy did not separate several price-related border instruments from standard tariffs. It also grouped a wide range of import-related non-tariff measures under a single residual category. Both limitations made it harder to trace contagion effects and compare policies across countries.

The distinction matters analytically. A minimum import price prevents market entry below a set threshold. An import price benchmark adjusts duty calculations by correcting declared values. A variable duty stabilises domestic prices in response to world market fluctuations. Collapsing these into a single tariff category obscures the mechanism through which each measure affects trade flows.

The same logic applies to instruments limiting how goods can flow into a market. Port restrictions, selective import channel restrictions, and distribution restrictions all limit market access, but through different points in the supply chain. Treating them as undifferentiated non-tariff measures prevented systematic analysis of where and how governments intervene beyond the border.

We have created 10 new intervention types to better capture border measures. Six fall under MAST chapters E, F, and P; four address market access mechanisms under MAST chapters C, H, J, and K.

• Import price benchmark: Policy actions establishing benchmark prices that customs authorities use to verify declared import values and calculate duties. They seek to prevent under-invoicing and protect domestic markets from under-priced imports.
• Minimum import price: Policy actions establishing minimum price thresholds that prevent importation of goods below specified levels, blocking market access for underpriced products rather than adjusting duty calculations.
• Other import charges: Policy actions imposing additional border charges beyond standard tariffs, including variable duties, customs surcharges, seasonal tariffs, and government service fees applied before customs clearance.
• Voluntary export-restraint arrangements: Policy actions securing voluntary export quantity commitments from trading partners to limit shipments to specific markets, preventing trade restrictions through negotiated volume controls.
• Voluntary export-price restraints: Policy actions securing voluntary export price commitments from trading partners to maintain minimum pricing levels, preventing trade restrictions through negotiated price floors rather than imposed border measures.
• Export price benchmark: Restrictions establishing price benchmarks for exported goods to verify declared values and calculate applicable export taxes, whether implemented through reference pricing or minimum price thresholds.

• Port restriction: Regulations requiring imported goods to pass through a designated port or ports of customs. For example, a country might mandate that imports of live animals be channelled through a single, specified customs office.
• Selective import channel restriction: Regulations that grant exclusive access or preferential treatment to select economic operators, including import monopolies held by state trading enterprises or rules requiring that certain commodities be traded only by specific government-owned companies.
• Distribution restriction: Regulations that control how imported goods reach domestic consumers through limitations on sales channels and market access, including measures confining sales to specific regions.
• Post-sales service restriction: Regulations that limit how exporters deliver customer support in importing markets, including measures requiring that after-sales services be provided by local service companies of the importing country.

The reclassification supports two analytical distinctions that were previously difficult to make. The new taxonomy captures new possible border and behind-the-border trade barriers. Users can now distinguish specific price mechanisms from tariffs. They can also identify specific actions limiting how goods and services can access and circulate within markets. This distinction is essential to understanding how trade policy is shaping supply chains.

We examined 2,329 interventions and reclassified 2,044. The reclassification covers interventions from November 2008 onwards, drawing from the following original GTA intervention types: import tariff, export tax, and import-related non-tariff measures, nes.

The reclassification proceeded in two tranches. The first focused on interventions falling under MAST chapters E, F, and P and was completed in summer 2025. The second focused on import-related non-tariff measures and was completed on 4 March 2026. Both tranches relied entirely on expert validation.

Full documentation for the new taxonomy, including detailed definitions and coding guidance, is available in the updated GTA Handbook.