Since the Great Depression of the 1930s, international economic cooperation has flourished on many issues. The Reciprocal Trade Agreements program of the United States laid the groundwork for the General Agreement on Tariffs and Trade (GATT), now subsumed within the World Trade Organization (WTO). Trade liberalization under WTO/GATT auspices has reduced tariffs on dutiable goods imports in developed countries from an average of 30 to 40 percent in 1947 to an average of around 4 percent today. The WTO General Agreement on Trade in Services has made significant initial progress in opening national services markets to companies based abroad. The WTO Agreement on Trade-Related Aspects of Intellectual Property Rights has, for better or worse, produced international harmonization in many aspects of patent, copyright, and trademark law. Bank regulators in the developed economies have cooperated through a series of Basel Accords. For roughly a quarter century, the International Monetary Fund orchestrated multilateral cooperation on exchange rates under the Bretton Woods system. And at the bilateral and plurilateral level, hundreds of investment agreements—standalone bilateral investment treaties and investment provisions in preferential trade agreements—afford a variety of protections to foreign investors in developed and developing countries.
Conspicuously absent from this list is international cooperation on migration. Although, as shall be seen, more cooperation exists than is widely recognized, it is largely restricted (outside of the European Union) to guest worker programs and measures that facilitate the temporary movement of skilled businesspeople and professionals. The legal rules governing the opportunity to establish permanent residence, to obtain citizenship and voting rights, and to secure long-term access to employment markets remain almost entirely outside international law with the exception of a few close-knit, regional arrangements.