An informal worker sells mobile phones from a street stand. Photo: MikeBlyth (Flickr)

A man selling toys on Sao Paulo’s streets, a woman grilling fish in crowded markets of Lagos and a handbag maker in Guangzhou might not seem to have much in common. But they are all part of the global informal economy, now estimated to be worth about $10 trillion a year.

Economic exchanges that are not taxed, monitored, or included in GDP measurements make up the informal sector. According to the Organization for Economic Cooperation and Development, more than half the workers in the world make their living this way.

Journalist Robert Neuwirth details the lives and challenges of informal workers in his new book, Stealth of Nations. Speaking of the $10 trillion estimate, Neuwirth says "That's an astounding figure because what it means, basically, is that if the informal economy was combined in one country, it would be the second-largest economy on Earth, rivaling the United States economy."

With innovative relationships and global supply chains, many entrepreneurs are thriving and prefer to stay ‘off the books.’ In Lagos, Nigeria, where 80 percent of the workforce is employed informally, locals call it the ‘economy of resourcefulness’. Street vendors grill fish caught in Europe and sell mobile phones smuggled from China.

Some entrepreneurs earn enough to travel out of Nigeria to purchase products to sell back home. "When you journey to the train station [in Guangzhou, China], you feel like you're in Africa because there's so many Africans located there,” Neuwirth says. “Africans have embedded themselves in society there in very direct ways, and there's a huge [informal] back channel of trade in China and Africa.”

The global scope of the informal economy is staggering. Governments and corporations are noticing traditionally ignored channels for revenue production. A market court in Lagos allows for the settlement of disputes between informal sellers and buyers. And, writes Marc Levinson in his review of Neuwirth's book in The Wall Street Journal, "In Morocco, the consumer-goods giant Procter & Gamble has built an entire network of wholesalers and agents and subagents to sell diapers and soap through merchants in villages so remote that they have no retail stores." Such relationships could indicate a trend in bridging the divide between formal and informal economies.

As informal workers integrate their business globally, many are torn between a desire for added security of infrastructure and support, and the solutions they’ve established. Certainly not all aspire to move into the formal sector with its complications of taxation and regulation.

With such a large magnitude, it’s impossible to ignore the importance of informal exchanges to society's economic survival. Workers continue to forge paths to prosperity through entrepreneurial solutions. For many, that means operating outside the law.

Erik Mandell is a graduate of Middlebury College in Vermont. He is currently pursuing a master's degree in public administration and global leadership at Portland State. Read his other contributions to Global Envision.