The value of exports from America's foreign-trade zones increased by 13.7 percent in 2013, to a record high $79.5bn in merchandise exported, according to figures released by the U.S. Foreign-Trade Zones Board in its Annual Report to Congress. At $835.8bn, the 2013 value of received merchandise into FTZs also reached a new high, surpassing the previous year’s record of $732.2bn – a 14.1 percent increase.

With Burger King planning to relocate there after completing its buy of coffee-and-donut chain Tim Hortons for about $11.4bn, Canada is emerging as the latest tax haven for U.S. firms fleeing a high tax code at home.