It provides protection for domestic producers, as well as has great impact on the foreign trade conditions of the state. Thus tariff policy has become an important macro economic policy.

• 后来，随着国家干预经济作用的增强，关税又被赋予经济调节的功能，它可以为国内的生产者提供保护，同时对本国的对外贸易条件会产生重要影响，关税政策成为重要的宏观经济政策。