Labor productivity growth powers economic growth. Yet growth in productivity has generally slowed over the past half century, except for a brief burst during the mid-1990s and early 2000s. Since 2004 output per hour worked has grown at a pace of just 1.4 percent—which is half its pace in the three decades after World War II. This slowdown in productivity growth is not unique to the United States: all of the major advanced economies have experienced similar declines in productivity growth. In this paper we consider explanations for the slowdown in productivity growth as well as the public policies that can help restore it.