Traditional weighted-average measures of trade distortions are widely used in analyzing global and regional reforms, despite well-known deficiencies. This paper develops and applies optimal aggregators for the real-world case of multiple countries and commodities with much more detailed...

This paper uses detailed data on bound and applied tariffs to assess the consequences of the World Trade Organization s December 2008 Modalities for tariffs levied and faced by developing countries, and the welfare implications of these reforms. The authors find that the tiered formula for...