Do tariffs matter for the extensive margin of international trade? An empirical analysis

With disaggregate tariff data we study the impact of changing tariffs on the range of goods countries export to the United States. Our probits with country and good effects show tariffs tend to have a statistically significant but small impact: at best 5% of the increasing extensive margin for 1989-1999 and 12% for 1996-2006 is explained by tariff reductions. This suggests the extensive margin has not amplified the impact of tariffs on trade flows to such an extent that the relatively moderate tariff reductions since WW II can explain the strong growth of world trade.