11 Nishizaki and Sugo (2001) said the estimation of co-integration of real wages and productivity indicate that the labor share tends to rise over a long term in tandem with labor productivity growth on the capital deepening because the elasticity of substitution of labor and capital is below 1. But the study said such equilibrium labor share growth could not explain the labor share rise in the 1990s. Similar estimation results were obtained for the Annual Report on the Japanese Economy and Public Finance 2005.