While Y represents global trade, matrix X is a set of control variables and ε is the notion of error. Although more and more countries are embracing the idea of free trade, protectionism recovered with the economic crisis of 1929 and remains a reality today. The principle of learning by doing, national security or unfair competition has also been proposed over time to justify the use of protectionism. Liberalization (free trade policy) and protectionism are two fundamental instruments for governments to control international trade, in other words, two different types of foreign trade policy. Free trade policy is the minimum of state intervention in foreign trade, developed by the supply and demand forces of the market economy, while protectionism provides for the protection of the internal market against international competition through the use of tariff and non-tariff instruments. . . .