NAFTA's and CUSFTA's impact on international trade

"This paper identifies the effects of preferential trade agreements on trade volumes and prices using detailed trade and tariff data. It identifies demand elasticities by developing a difference in differences based method that exploits the fact that the additional wedge driven between consumption patterns in a liberalizing versus a non-liberalizing country is directly related to the tariff reduction. Supply elasticities are identified by using tariffs as instruments for observed quantities. Analysis of world-wide trade data for 5,000 commodities shows that NAFTA and CUSFTA have had a substantial impact on international trade volumes, but a modest effect on prices and welfare. NAFTA and CUSFTA increased North American output and prices in many highly-protected sectors by driving out imports from non-member countries"--National Bureau of Economic Research web site.