Freedom of movement for workers

Most developed countries have foreign aid programs that aim to alleviate poverty and foster economic growth in less developed countries, but with very limited success. A large body of evidence indicates that the root of the economic development problem is cross-country differences in the productivity of labor. If workers are much more productive in one country than in another, the obvious way to help people in less developed countries is to allow them to help themselves by moving to places where they can be more productive. Yet immigration laws severely constrain such movement.