Article dans une revue: We study the evolution of labor shares in 1995-2014, while taking into account international trade based on value added concepts. Declines in labor shares accelerate in 2001-2007, concurrently with global value chain (GVC) participation, after which there is no trend for both. We develop a gravity-based instrument for GVC participation and find that the acceleration in the decline in labor shares is caused by increased intensity of forward GVC participation. The insertion of China into GVCs has a disproportionally large effect through this mechanism. Declines in labor shares are shouldered mostly by less skilled workers in fabrication functions. Relatively capital abundant countries participate more in forward GVCs linkages, which is associated with greater upstreamness within GVCs and increases in capital intensity. Forward GVC participation is associated with international vertical integration of both upstream intermediate input production and of offshoring of downstream assembly.