Describe main reason for trade barriers and how they influence an economic system. plz help me

Sure, To start off trade barriers influence the economic system by adjusting as I would say or raise prices and reduce available quantities of goods

Explanation: Basically, Trade barriers such as ''tariffs'' raise prices and reduce available quantities of goods and services for U.S. businesses and consumers, which results in lower income, reduced employment, and lower economic output, How does trade barriers affect the economy? you may ask

''A trade barrier has resource-allocation effects because it alters a domestic price ratio: it raises the domestic price of import-competing activities relative to the domestic price of exportables, and hence introduces a wedge between the domestic relative-price ratio and the opportunity costs reflected in relative''.

hope this helped a little :)

answer; decipher the motives for why people behave the way they do;