New “artificial intelligence” (AI) technology promises to bring dramatic social and economic changes, demanding major policy changes. In intellectual property and antitrust law, AI will exacerbate a damaging trend: across all major sectors of the economy, proprietary information technology is increasing the market dominance of large firms. This trend might not seem like bad news, but it is evidence of a slowdown in the spread of technical knowledge throughout the economy. The result is rising industry concentration, slower productivity growth and growing wage inequality. The key challenge to IP and antitrust policy will be counter this trend yet maintain innovation incentives.