When Japan experienced high economic growth, its society was characterized by low inequality in income, a high saving rate and a low consumption rate. However, after Japan's transition to slow economic growth, it was said that the society lost income mobility, and the inequality among households deteriorated. In addition, the aggregate household saving rate dropped drastically. Meanwhile, consumption expanded, which gave people more options regarding their expenditure. With this background, this thesis examines the impacts of these changes-- income mobility over time, savings rate changes, and intra-household allocation--using a long run panel data set for Japan. Chapter 1 studies income mobility in Japanese society. Household income mobility at the macro level is measured by six different methods. The results show that as a whole, household income mobility became lower in the long-run. At the micro level, unconditional micro income mobility indicated that it is possible that poorer people would catch up with richer people. Finally, conditional micro income mobility also shows that there exists conditional convergence. In Chapter 2, the causes for the decrease in the aggregate household saving are analyzed. The aggregate time series analysis reveals that the increase in the ratio of the aged population ratio partially explains the sharp decrease in the household saving rate. By using household level panel data, it was found that savings driven by the motive of home ownership could partly account for this decrease in the saving rate. The increasing burden of education expenditure is among the strongest candidates for explaining the change. Finally, some weak indirect evidence in support of the target saving hypothesis is found. In Chapter 3, the characteristics of intra-household allocation are discussed. Using the Slutsky symmetry test, the unitary model could not be rejected for the consumption behavior of one-person households. Meanwhile, the tests for SR1, distribution factor proportionality and linearity indicated that the collective model might explain the consumption behavior of two-person households. Finally, the hypothesis that three-person households could be represented by the collective model for two-person households could not be rejected.