This paper focuses on how the household saving rate should be measured. The current method used in China to measure the saving rate is compared with that used in the U.S. Significant differences in concept and scope are discovered. Using these differences as a basis, we make relevant adjustments to the official measurement and recalculate the household saving rates of the two countries on a comparative scale. Our results show that the average of the Chinese household saving rate during the 1992-2004 period falls from 29.4 to 22.9 percent, and is lower than 20 percent in 2000, 2001, and 2003. The gap between China's household saving rate and that of the U.S. narrows by 8.6 percent on average and the adjusted difference is merely 17.5 percent on a comparable scale. It is therefore reasonable to conclude that the difference between the household saving rates of these two countries is in fact much smaller than is often suggested. Our study also shows that the household saving rates of these two countries are experiencing the same decreasing trend, but that both have increased slightly since 2002. Copyright 2008 The Authors. Journal compilation 2008 International Association for Research in Income and Wealth Published by Blackwell Publishing.

Ni-based single crystal (SC) superalloys are widely applied in the turbine blades of advanced aero-engine due to their excellent heat resistance. Rafting is a major degradation mode of SC under creep damage. In this study, the morphology evolution and probability characteristic of shape parameters are investigated for cuboidal γ´ phase during creep rafting. Three groups of SC creep tests are carried out at 850 °C and 600 Mpa along [001] direction. Scanning electron microscope (SEM) is used to observe the microstructure of SC at four different creep times including 0 h, 8 h, 16 h and 64 h. In addition, an image processing program is developed to identify the length (normal to uniaxial stress) and width (parallel to the stress) of each γ´ phase. Two interesting findings of this investigation can be summarized as: 1) During the N-type rafting of SC, the vertical matrix channel widths are gradually decreased, and the γ phases near the vertex of the cuboidal γ´ phases disappear 2) The length, width of γ´ phases both obey lognormal distributions during creep rafting, and the standard deviations change slightly for the width, but increase significantly for the length. These above findings are of significance to multi-scale probability modeling for creep deformation and fracture.