Book excerpt: An eye-opening account of the informal economy around the globe, Stealth of Nations traces the history and reach of unregulated markets, and explains the unwritten rules that govern them. Journalist Robert Neuwirth joins globe-trotting Nigerians who sell Chinese cell phones and laid-off San Franciscans who use Twitter to market street food and learns that the people who work in informal economies are entrepreneurs who provide essential services and crucial employment. Dubbing this little-recognized business arena with a new name—”System D”—Neuwirth points out that it accounts for a growing amount of trade, and that, united in a single nation, it would be the world’s second-largest economy, trailing only the United States in financial might. Stealth of Nations offers an inside look at the thriving world of unfettered trade and finds far more than a chaotic emporium of dubious pirated goods.