David Autor, one of the country’s most celebrated labor economists, took the stage, fumbled for his own PowerPoint presentation and then explained that there was plenty of evidence showing that technological change explained a great deal about the rise of income inequality. Computers, Autor says, are fundamentally different. Conveyor belts and massive steel furnaces made blue-collar workers comparatively wealthier and hurt more highly skilled craftspeople, like blacksmiths and master carpenters, whose talents were disrupted by mass production. The computer revolution, however, displaced millions of workers from clerical and production occupations, forcing them to compete in lower-paying jobs in the retail, fast-food and home health sectors. Meanwhile, computers and the Internet disproportionately helped people like doctors, engineers and bankers in information-intensive jobs. Inequality was merely a side effect of the digital revolution, Autor said; it didn’t begin and end in Washington.