In an article on charter cities in The Atlantic, Sebastian Mallaby has a good summary of how the Hanseatic League of cities emerged in the Middle Ages from what was arguably the first charter city.
When Henry the Lion founded Lübeck, he wrote a charter that specified “a set of ‘most honorable civic rights,’ calculating that a city with light regulation and fair laws would attract investment easily.” The city itself was a dramatic success. It also spawned clone cities that copied its charter. See the article for the details in this remarkable historical episode. (It even has pirates!)
In the discussion of the modern proposal for charter cities, the article picks up the language of “neo-colonialism” that some charter city critics use in an appeal to emotion. Yet, the article uses the term dispassionately and gets the logic exactly right: If it’s neo-colonial for a family to move from a poor country to a charter city, it’s also neo-colonial for the same family to move to Vancouver. In the end, the important ethical question is whether people from poor countries should have more choices about where to live.
If the critics who appeal to emotion want to frame the debate in terms of colonialism, we should distinguish the coercive brand of colonialism that the British used to invade India from the opt-in brand of colonialism that Indians employ when they migrate to London.
If you’re interested in additional background after reading The Atlantic article (and don’t mind a less lively and readable style), you can refer to a paper I wrote for the Center for Global Development.