The population of the world can never be balanced because each nation has its territorial integrity and population policies. Except there is a bilateral agreement between two nations, no nation can be forced to accept immigrants to balance their population quota. Racism will be another reason why it might be difficult to facilitate the distribution of population among different nations. Most people will never want to see Africans in their neighborhood because they can't t afford to live around them.
But there is population distribution going on currently. Nations like Canada, the UK, and the US always open their boundaries to immigrants to help in contributing to the workforce of the nation. Most nations use immigrants to cover up areas that have shortage of labor. The only difference is that they usually attract the best brains, rich or skillful. While those that cannot afford this immigration process have no chance of moving to these nations.
But it will be ideal to have a world where there will not be restrictions on movement from one country to another. This will be possible if many nations achieve economic development.