why close off an economy 
although totally closed economies are essentially nonexistent today governments may still close off a specific industry or sector of their economy from international competition some oil producing countries for example have a history of prohibiting foreign petroleum firms from doing business within their borders the argument in favor of a partially closed economy is that a completely open one runs the risk of becoming overly dependent on imports resulting in a severely lopsided balance of trade also domestic producers may suffer because they cannot compete at low international prices therefore governments may use trade controls like tariffs subsidies and quotas to support domestic enterprises this policy is often referred to as protectionism the united states for example which has relatively low tariffs overall imposed a 25 tariff on steel imports and a 10 tariff on aluminum imports in 2018 in the name of protecting domestic producers from unfair foreign competition particularly from china 5 in 2022 those rules were amended 6measuring how closed an economy isone way to assess the degree to which an economy is open or closed is by measuring the country s imports and exports as a percentage of its gross domestic product gdp by that measure the african nation of sudan may have the most closed economy today using the most recently available figures imports represent just 1 0 of sudan s gdp while exports represent 1 2 in the u s by comparison those figures are 15 4 and 11 6 respectively 78