Once negotiated, multilateral agreements are very powerful. They cover a wider geographic area, giving signatories a greater competitive advantage. Since Adam Smith published The Wealth of Nations in 1776, the vast majority of economists have accepted the thesis that free trade between nations improves overall economic well-being. Free trade, generally defined as the absence of tariffs, quotas or other government barriers to international trade, allows each country to specialize in products that it can produce cheaply and efficiently compared to other countries. Such specialization allows all countries to earn higher real incomes. While virtually all economists believe that free trade is desirable, they do not agree on the best way to move from tariffs and quotas to free trade. The three fundamental approaches to trade reform are one-sided, multilateral and bilateral. U.S. tariffs are at their lowest in history. Before the Second World War, they were up to 40% for some imports. Today, customs revenues account for less than 5% of the volume of imports and the dollar, and many imports are exempt from tariffs and quotas.

Non-tariff barriers have also been largely eliminated, but not completely. There are three different types of trade agreements. The first is a unilateral trade agreement[3] if one country wants certain restrictions to be enforced, but no other country wants them to be imposed. It also allows countries to reduce the amount of trade restrictions. It is also something that is not common and could affect a country. Critics of bilateral and regional approaches to trade liberalization have many additional arguments. They propose that these approaches undermine and supplant the MULTILATERAL approach of the WTO, which must be favoured for global use on a non-discriminatory basis, rather than supporting and complementing it. Therefore, the long-term outcome of bilateralism could be a deterioration of the global trading system into competing and discriminatory regional trading blocs, which could lead to additional complexity that complicates the flow of goods between countries. In addition, the reform of issues such as agricultural export subsidies cannot be effectively addressed at the bilateral or regional level.

Even in the absence of the constraints imposed by the most favoured nation and national treatment clauses, it is sometimes easier to obtain general multilateral agreements than separate bilateral agreements. In many cases, the potential loss resulting from a concession to a country is almost as great as that which would result from a similar concession to many countries. The benefits to the most efficient producers from global tariff reductions are significant enough to warrant substantial concessions. Since the implementation of the General Agreement on Tariffs and Trade (GATT, 1948) and its successor, the World Trade Organization (WTO, 1995), global tariffs have declined considerably and world trade has increased. The WTO contains provisions on reciprocity, the status of the most favoured nation and the domestic treatment of non-tariff restrictions. She has been involved in the architecture of the most comprehensive and important multilateral trade agreements of modern times.