Answer:
High Labor Costs
Explanation:
The United States has very high labor costs relative to most of the rest of the world. This is simply because the United States, as a highly developed country, has very high average wages in all industries.
This is a problem for manufacturing companies because it raises their labor costs. And the problem becomes bigger for the United States as a country in a globalized economies: companies can simply choose to locate to other countries where labor costs are lower, like China, Vietnam or Bangladesh.
This is perhaps the main reason, according to many economists, why American manufacturing has declined in many areas of the country, particularly in the Rust Belt.