Online Extra: The Sharing Economy

As a professor at Yale Law School, Yochai Benkler doesn't seem like a prime candidate to rewrite the field of economics. But in a couple of papers, most recently "Sharing Nicely: On Shareable Goods and the Emergence of Sharing as a Modality of Economic Production," he suggests that the Internet and cheap computers are spurring a new method of producing economic value besides the market and the traditional company. He calls it commons-based peer production.

Open-source software, song sharing, the volunteer-written online encyclopedia Wikipedia, and other activities, he contends, require neither traditional corporate oversight nor monetary incentives to create real value. And that's likely to both threaten some existing companies and create entirely new ones, as it has with search engine Google (GOOG ) and Skype Technologies, a provider of free Internet phone service.