A new report from UN Trade and Development (Unctad) examines how uneven tariff increases are affecting access to the US market and what this means for developed, developing and least developed countries.

The analysis shows a more restrictive and uneven trade landscape, with clear losses for some exporters but new opportunities for others.

Trade policy changes can shift winners and losers in global markets, Unctad points out.

When governments adjust tariffs, preferences or other trade costs, they change prices and competitive conditions. Some exporters gain advantages while others lose ground, reshaping trade flows and sourcing decisions, it explains.

Recent US trade measures demonstrate how these shifts unfold in practice.

In the context of recent US trade measures, the scale and direction of tariff changes have had measurable implications for exporters’ competitiveness in accessing the US market, the report indicates.

It notes that the effects have been uneven, as suppliers have moved from largely uniform tariff treatment to sharply differentiated tariff levels, depending on the origin.

For instance, as of early this year, US imports of South African wine are about 17 percentage points more expensive relative to other wine-exporting countries than they were in 2024.

Although product quality and variety continue to influence sourcing decisions, these relative tariff differences are likely to shape procurement strategies and may gradually shift trade flows, the report outlines.

According to the report, changes in trade policy generate gains and losses among exporters, influencing competitive dynamics across foreign suppliers.

The report notes that divergent tariff increases can further affect trade patterns, as importers adjust sourcing toward suppliers facing relatively lower tariff rates.

It points out that recent tariff changes have made market access more restrictive and uneven, altering competition between exporters.

Uneven tariff shifts can create new exports opportunities for some developing countries, especially when combined with preferential programmes, the report highlights.

For many trading partners, the recent US tariff measures are expected to alter relative competitiveness in the US market.

In several product categories, tariffs have increased more sharply for some large emerging economies, including Brazil, China and South Africa, resulting in comparatively smaller increases for other suppliers, the report indicates.

In such cases, exporters facing relatively lower tariff adjustments may experience improved cost competitiveness, it notes.