The United States has added 1.2 million jobs in manufacturing over the past eight years. Before you cheer for the revival of American manufacturing, consider the reason for all that job growth: abysmal productivity performance.

Standard measures of the U.S. labor market look pretty good. The unemployment rate is low, and job growth has been steady.

Big business is getting bigger, and workers’ slice of the economic pie is getting smaller, especially in the transportation and warehousing sector.