E.g. We don't allow Africans to refine products so that we can maintain our economies in the West. E.g. raw cocoa sells for $0.01, but when refined into chocolate, its worth $1.
We put high tariffs on the refined produce and low on the raw materials to keep us in control (i.e. we refine everything to make the real $$). Then we give back a small proportion of the profit in "aid".
Upside is that we protect our economies.
Downside is poverty in Africa.
As a twist on this, the Chinese are starting to deal directly with Africa on much fairer terms and this is upsetting the US/EU.