Under a system of completely free trade, capital and labor would be employed
wherever conditions are most favorable for production....
But the migration of capital and labor presupposes not only complete freedom of
trade, but also the complete absence of obstacles to their movement from one
country to another...
But whatever may be the prerequisites for the development of international trade,
protective tariffs can accomplish only one thing: to prevent production from being
carried on where the natural and social conditions are most favorable for it and to
cause it to be carried on instead where conditions are worse. The outcome of
protectionism is, therefore, always a reduction in the productivity of human labor.The freetrader is far from denying that the evil that the nations of the world wish to
combat by means of a policy of protectionism really is an evil. What he maintains is
only that the means recommended by the imperialists and protectionists cannot
eliminate that evil.
-Ludwig von Mises, Liberalism: A Socio-Economic Exposition