What do we know about preferential trade agreements and temporary trade barriers?

Introduction Two of the most important trade policy developments to take place since the 1980s are the proliferation of preferential trade agreements (PTAs) and the ebb and flow of national use of temporary trade barriers such as anti-dumping, safeguards and countervailing duties. Nearly 600 PTAs have now been notified to the World Trade Organization (WTO), with nearly 400 of these in force as of 2013 (World Trade Organization 2013). With respect to temporary trade barrier (TTB) policies, major economies such as Brazil, China, India, Mexico and Turkey went from being TTB nonusers in the late 1980s to the situation whereby a substantial share of their import product lines at some point over the subsequent 20 years became covered by these additional forms of nontariff protection (Bown 2011, 2013a). Furthermore, some of these countries, as well as a number of other major TTB users such as Argentina, Australia, Canada, the European Union (EU), Peru and the United States, also became involved in significant new PTAs during this period. Despite the empirical importance of PTAs and TTBs and the common feature that each can independently have quite discriminatory elements, relatively little is known about the nature of any relationships between PTAs and TTBs. For example, do PTAs lead to more or less use of TTBs overall? Does the composition of the group of trading partners targeted by TTBs change after the implementation of a PTA? That is, after PTAs are implemented, do countries tend to impose TTBs on PTA nonpartners, further reinforcing the preferences already inherent in the PTA? Or do forces conspire to shift TTB use towards PTA partners, in an implicit attempt to restore more nondiscriminatory, most-favoured-nation (MFN)-like treatment that the implementation of the PTA would have disrupted? Does the use of TTBs depend on the existence and type of PTA rules concerning such use, and does this differ for free trade agreements versus customs unions? Furthermore, do PTA partners tend to coordinate TTB activity against third countries in response to common shocks? Finally, what are the political-economic channels that would explain any patterns in the data that emerge?.