The industry staging pattern of U.S. tariff reductions under the NAFTA is explained and analyzed. A trade weighted tariff for Mexican imports is calculated for each SIC category for each year between 1994 and 2007. Industry characteristics are investigated to see which ones may explain the pattern of pre-NAFTA as well as the staging pattern of the duty reductions under NAFTA. The tariff structure during the NAFTA phase-in is highly correlated to the pre-NAFTA tariff structure. Low industry employment growth, low industry wages, a high percentage of production workers, a large industry, a high import price elasticity, and agricultural products are associated with higher tariffs. Once the pre-NAFTA tariffs are controlled for, NAFTA-transition tariffs appear higher in industries with high wages, a low percentage of imports entering under the HTS Section 9802 provision, and a high percentage of production workers.