However, many economists believe that the dynamic benefits of free trade could be greater than the static benefits. Dynamic benefits include, for example, pressure on firms to tackle foreign competition more effectively, the transfer of skills and knowledge, the introduction of new products, and the potential positive effects of greater adoption of trade law. Thus, trade can affect both static effects and production (dynamic effects). All global trade agreements are multilateral. The most successful is the general agreement on trade and customs. Twenty-three countries signed the GATT in 1947. The aim was to reduce tariffs and other trade barriers. In addition, some products do not use the same production factors over their life cycle.  For example, when computers were first introduced, they were incredibly capital-intensive and needed a highly skilled workforce. Over time, as the volume increased, costs decreased and computers were mass-produced. In the beginning, the United States had a comparative advantage in production; but today, while computers are mass-produced by relatively unskilled labour, the comparative advantage has shifted to countries where labour is plentiful and cheap. And other products can use different production factors in different countries.
For example, cotton production is very mechanized in the United States, but it is very laborious in Africa. The fact that the factors of production may change does not negate the comparative advantage theory; it simply means that the package of products that a nation can produce relatively effectively can change only its trading partners. Hong Kong, Zurich and Paris have crowned a new list of the most expensive cities. A weaker dollar has led to a relative decline in costs in the United States. In economic theory, the cost of all factors of production that could cross borders would have an equal cost in all commercial countries if the factors of production are entirely mobile. This would mean that the basis of the comparative advantage for trade between countries would decrease and that there would ultimately be less international trade. They are easier to negotiate than multilateral trade agreements because they cover only two countries. This means that they can come into force more quickly in order to reap the commercial benefits more quickly.
If negotiations for a multilateral trade agreement fail, many countries will instead negotiate a series of bilateral agreements. A current account surplus or deficit may be affected by the economic cycle. Therefore, if our economy grows rapidly, the demand for imports will increase, as consumers can afford to buy more and businesses will need parts and stocks to grow.