The idea that rising productivity due to automation will make human laborers superfluous is hardly a new one: It motivated the original Luddites almost 200 years ago to smash mechanical looms. But while this notion is grounded in a pretty simple economic fallacy, it's proved harder to kill than a horror movie slasher.
The most recent attempt to revive the theory comes from techie Marshall Brain, in the form of the warning that robots will render us all perfectly redundant in the coming decades. The problem here is much like that exhibited in William Greider's much ballyhooed antiglobo screed One World, Ready or Not: The Manic Logic of Global Capitalism. Greider did extensive journalistic legwork, collecting data and anecdotes from around the world, and Brain certainly knows his tech. In both cases, alas, this leads to a false sense of security: confident in their knowledge of the particulars of their subject matter, both authors neglect to guard themselves against basic errors in economic theory. In the Salon piece linked above, Robert Reich provides the counterpoint to Brain's doomsaying. The same fallacy is viciously exposed by Paul Krugman in his review of Grieder's book.