A new study from Massachusetts shows that "in 2004 there were 424,172 sole proprietors in Massachusetts, defined as business owners who work alone, or may work with other sole proprietors and/or wage and salary employees." (We call them independent workers or freelancers.) The study was released by the Enterprise Center, an organization in Massachusetts dedicated to assisting entrepreneurs and small businesses. A more astonishing figure: "Of the net additional jobs created in Massachusetts between 1994 and 2004, 30.2 percent were proprietorships with no wage and salary employees." This is analogous to the report recently issued by New York City's forward-thinking comptroller, Bill Thompson, which showed that independent workers are crucial to the local economy. It's beginning to look as though independent workers are driving economic growth all over.