Market access, of which tariffs are a central but not the only parameter of mutually beneficial trade, was one of the top priorities in the only multilateral trade negotiating round launched in the WTO’s 30-year existence in 2001, and never concluded.

After an auspicious start, the Doha Round of WTO negotiations – named for the city where they originated – slowed, then became mired in acrimonious finger-pointing before finally collapsing irreversibly in 2015. Five years after the start of the Doha Round, in 2006, then US Trade Representative (USTR) Susan Schwab remarked that, "[T]he Brazil’s, the China’s, the India’s of this world can and should be expected to participate in this negotiation, including opening their markets to benefit other developing countries because the sad fact is that developing countries, 70% of the tariffs, of the duties paid by developing countries, are paid to other developing countries." WTO negotiations on tariffs never really regained their early momentum after it became clear that high-tariff members were not interested in making reciprocal cuts.

As a result, current average tariff levels continue to vary substantially among WTO members. The WTO issues summaries of these rates at both the "bound" and "applied" levels. The term "bound" refers to the product-by-product rates that each WTO member has legally committed to, as reflected in its WTO tariff schedule, while "applied" rates are the actual tariffs in place at any given time. For example, Country X could bind its tariffs for watches at 10% yet later choose to apply those tariffs at a lower level of 5%.

There is a small group of countries that have zero-level or near-zero tariffs. For example, Singapore has an average bound rate of 8.8% but an applied rate of zero. Similarly, Brunei has an average bound rate of 25.4% but an applied rate of 0.5%. Of course, those countries could raise their tariffs in the future to bound rates without violating their WTO obligations.

Among the largest trading countries, the United States ranks at the low end of tariff levels at an average bound rate of 3.4% and applied rate of 3.3%. (This does not account for its latest tariff increases against China.) The European Union’s (EU) average bound tariff is 4.9%, and the applied rate is 5%.