2004 Volume 3 Pages 81-102
In this paper, we analyzed the structural change in log production during the period. First, Cobb-Douglas production functions were estimated for each year over 1970-2000 using cross-section data. Then, we derived the technical progress ratio and looked into the changes in the production function coefficients of labor, forestry machine and highly efficient forestry machine. As a result, it is found that the technology of Japanese log production has been increasingly characterized by the increasing returns to scale. During the 1990s, labor had the highest average contribution rate. Although the contribution rate of highly efficient machine was in low level, it was increasing and the effects of the productivity advance were around I 00% with some regions of more than 100% of the ratio, while the values of labor and forestry machine leveled off or decreased. Thus it is considered that the introduction of highly efficient machines had some eiTect in substituting decreasing labor.
