From the Document: "Rules of origin (ROO) are laws, regulations, and procedures used to determine the country of origin of an imported product. They are a significant part of international trade policy because ROO are needed to properly assess tariffs, enforce trade remedies (such as antidumping and countervailing duties) or quantitative restrictions (tariff quotas), and statistical purposes. Other commercial trade policies are also linked with country of origin determinations, such as labeling and government procurement regulations. Given Congress' authority to regulate foreign commerce, it may consider how rules of origin fit into overall U.S. trade policy as well as future trade negotiations. The methodology used to determine the country of origin, can be straightforward--as long as the parts of a product are manufactured and assembled in one country. However, when a finished product's component parts originate in many countries, as is often the case in today's global trading environment, determining origin can be a more complex process."
CRS Report for Congress, RL34524
Congressional Research Service: https://crsreports.congress.gov/