Productivity growth in a sector or economy is the economic basis for improvements in workers' wages. Recent growth of domestic and foreign outsourcing in developed economies greatly complicates the measurement and interpretation of this key economic indicator and may result in inflated and misleading increases in productivity statistics. In the context of United States manufacturing, this article points to several pieces of evidence that suggest these effects of outsourcing and offshoring on productivity measures are significant. These factors may help explain why wage growth for most United States workers has been relatively low in spite of high measured productivity growth.