The main arguments used in favour of protection are the "infant industry" argument, the "diversification of industry" argument, the "employment" argument, the "conservation of natural resources" argument, the "key industry" argument, the "self-sufficiency" argument, the need to check unfair competition and the need to correct a persistent deficit in the balance of payments.
The "infant industry" argument is probably the most economically sound argument in favour of protection. This argument applies to countries with potential advantages to reap large economies of scale in certain industries which are unable to compete in early stages of their development with established industries in the world. Thus, protection will enable countries, particularly the developing countries, to use their resources more efficiently in the development of industries in which they have potential advantages. Without protection, the infant industry will not survive, and scarce economic resources will have to be diverted from their most efficient use. With protection, the infant industry will have a chance to grow. Once it is large enough, it will be able to produce as cheaply, if not more cheaply, as the foreign rivals and thus will be able to contribute its full share towards maximizing world output.