NYU economist Paul Romer is what Chrystia calls an “ideas entrepreneur.” He revolutionized the study of economic growth with his research on the power of ideas. He shook up the field of higher education with his company that offered online homework problems that were graded by computer. Now Romer has set out to alleviate world poverty. For his new project, Romer set up a nonprofit organization dedicated to convincing governments across the developing world that they should cede a portion of their territory to an external authority in order to create a “charter city” in which new rules would make it attractive for skilled immigrants, unskilled migrants and businesses to come and settle.