Removing artificial restrictions on a free market system will increase overall productivity. It will certainly increase global GDP to remove barriers to free movement of people.<p>Imagine that people could NOT move between various states in the United States. Do you think this would improve the GDP of the US? Hey, the SF programmers would no longer need to put up with those pesky developers immigrating from the midwest and reducing their 300K salaries to 140K. However this&#x27;d be true for the guy working in the grocery store as well for 120K a year - since he&#x27;d also not compete with anyone else and gladly take his share of your 300K salary.<p>People hate monopolies until they are the monopoly. Then they defend it tooth and nail. Native-born citizens, due to the chance event of where they&#x27;re born, extract monopoly rents to the detriment of the global GDP.