His latest contribution has been in trying to replicate the success of charter cities and make it an engine of economic growth in developing countries. He promoted this idea in a TED talk in 2009. Romer has argued that with better rules and institutions, less developed nations can be set on a different and better trajectory for growth. In his model, a host country would turn responsibility for a charter city over to a more developed trustee nation, which would allow for new rules of governance to emerge. People could "vote with their feet" for or against these rules.
The government of Honduras has recently considered creating charter cities, though without the oversight of a third-party government, which some argue is neo-colonialism. Romer served as chair of a "transparency committee" but resigned in September 2012 when the Honduran government agency responsible for the project signed agreements with international developers without involvement of the committee.