1. Commercial Policy
Commercial policy refers to any governmental measure that discriminates against foreign suppliers

2. Arguments for Commercial Policy
To Protect Domestic Industries;
To Save Jobs;
National Security and Defense;
To Protect an Infant Industry;
To Raise Revenue for Government;
Others

3. Tariffs
A Tariff is a tax levied on imports. Tariffs can be Ad Valorem or Specific.
The Ad Valorem tariff is expressed as a fixed percentage of the value of the traded commodity.
The Specific tariff is expressed as a fixed sum per physical unit of the traded good.