During the second half of the twentieth century, trade barriers have in general: declined quite substantially both in the U.S. economy and in the global economy. declined quite substantially in the U.S. economy but not in the global economy. increased quite substantially in the U.S. economy and in the global economy. increased quite substantially in the U.S. economy but not in the global economy.The race to the bottom scenario of global environmental degradation is explained roughly like this: Companies seek to reduce their costs of operations on plant and equipment design and this results in higher levels of pollution. Companies seek the lowest market prices on products in order to gain market share, resulting in inferior goods and increased waste and pollution. Profit-seeking multinational companies shift their production from countries with strong environmental standards to countries with weak standards, thus reducing their costs and increasing their profits. Companies seek to influence environmental legislation standards are set to the lowest possible standards in the USA in order to maximize profits