In at least 17 formal WTO disputes during the period, the complaining country alleged that the respondent violated some element of the GATT/WTO provisions on customs valuation.

There is a small but growing empirical literature examining how these administrative channels affect trade; indeed, governments have recently put a priority on them through the WTO’s newly negotiated Trade Facilitation Agreement. The World Bank’s _Doing Business_ reports are the best known source of comprehensive data about time delays and related problems associated with moving goods across a border. Djankov, Freund and Pham (2010), for example, use these data to estimate a gravity model of trade and find that each additional day of delay before shipment reduces trade by more than 1 percent. Furthermore, Volpe Martincus, Carballo and Graziano (2015) utilize detailed export transaction data from Uruguay to estimate the impact of customs delays on firm exports. Finally, research using data on customs valuation to examine bureaucratic corruption and tariff evasion includes Javorcik and Narcisco (2008) for Eastern Europe and Mishra, Subramanian, and Topalova (2008) for India.

# **4 The Historical Evolution of Border Barriers Under the GATT**

Focussing thus far on trade barriers imposed at the border, we have characterized the contemporary landscape of trade policy as both having significant heterogeneity in applied tariffs, but also as being littered with numerous other border barriers. Collectively and cumulatively, the status quo is of trade policy marked by variation across countries, products, and trading partners. But how did the international trading system arrive at this point? With only a few exceptions, our discussion of history thus far has been limited to the evolution of trade policy since the 1995 inception of the WTO. Here we briefly appeal to a longer view of the history of the multilateral trading system by focusing on major trade policy developments taking place over the period spanning 1947-1994, covering the full GATT era.

We begin with the level of tariffs for the major economies at the outset of the GATT negotiations in 1947 that established the new multilateral trading system.<sup>65</sup> After reporting on the subsequent evolution of applied tariffs, we introduce the major exceptions to the GATT rule that countries should limit the form of their import protection to their applied MFN tariffs and we assess recently released data from the GATT Archives on their use. One key observation is that protectionist forces have been pushing back against trade liberalization since the inception of the multilateral system. Amidst a general decline in tariffs, new trade restrictions emerged. Thus still open questions for researchers to pursue include quantifying the importance of this push-back and further clarifying how it relates to the policy substitution that we documented in Section 3 as having arisen today.

The GATT members introduced a number of contingency clauses regarding the use of trade restrictions when they drafted the agreement because they understood that changing economic

> 65The historical context matters, as the GATT system arose and was shaped by a number of major geo-political events. These include the catastrophic economic policies of the 1930s Great Depression era, the devastation of Western Europe and Japan during World War II, and the rise of the Cold War between the United States and Soviet Union. See, for example, Irwin, Mavroidis and Sykes (2008) for the negotiating origins of the GATT.

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