"If that were truly the case, as critics of the left and right are charging, then low-wage backwaters like Rwanda and Zimbabwe would receive the lion's share of investments from the West.[...]"
The author is convinced that his readers are very stupid. The real search is for the most cost-effective workers. If worker B will work for a salary that is half of what worker A demands, but worker B is one-third as productive, then worker B, even though "cheaper" is not as cost-effective
You're confusing the Marxist-Buchananists.