Publications

This study examines how declining labor share affects macroeconomic outcomes and fiscal sustainability in Japan—the country with the most advanced population aging globally. While previous research has documented the global trend of declining labor share, its implications for fiscal policy in aging societies remain underexplored. Using a life-cycle general equilibrium model in the Auerbach–Kotlikoff tradition, we calibrate parameters to match Japan’s economic and demographic characteristics, incorporating country-specific institutions such as public pension, health insurance, and long-term care systems. Our analysis reveals that when capital share increases by 3 percentage points between 2025–2060, it generates fiscal relief equivalent to approximately 3 percentage points in consumption tax by 2070 through enhanced capital accumulation. More significantly, this declining labor share amplifies the efficacy of pension reforms, potentially yielding savings equivalent to over 12 percentage points in consumption tax. Our findings suggest that declining labor share, when coupled with appropriate policy reforms, may benefit fiscal sustainability in rapidly aging societies with high public debt.

This study examines trends in earnings, income and wealth inequality among households in Japan from 1984 to 2019. Our findings reveal that inequality in all three domains has increased over the last decades, but due to different underlying factors. The rise in earnings and income inequality is primarily driven by demographic aging, with an increasing proportion of elderly households who typically exhibit higher inequality levels. The growth in wealth inequality is evident not only in the overall population but is particularly pronounced among the young. This trend is largely attributed to a significant rise in the number of households that possess extremely low wealth. Key factors contributing to inequality trends in Japan include aging demographics, shifts in household structure, and major macroeconomic developments such as the financial bubble period and the prolonged economic slow-down that followed.

This paper analyzes the time trend of household consumption in Japan between 1981 and 2020, using microdata from the Family Income and Expenditure Survey (FIES). We examine how the trends in the levels, shares, and growth of consumption vary across categories of consumption, items, and age groups, and assess changes in consumption inequality over time. Our analysis shows that consumption inequality mildly increased, driven primarily by the trend of service consumption and a shift in the age distribution. Additionally, we estimate the life-cycle profiles of consumption and find that the age component of total consumption follows a standard hump-shaped pattern, but varies significantly across goods and service categories and item groups. Finally, using the estimated age profiles of different consumption items, we project how aggregate consumption and its composition may evolve as Japan’s population ages in the coming decades.

Japan faces rapid and severe demographic aging and rising fiscal deficits due to increasing expenditures and shrinking tax revenues. This paper studies how an inflow or an outflow of foreign workers affects projections of macroeconomic and fiscal variables. We show that foreign workers help slow down a decline in labor force and mitigate fiscal pressures, but effects are not large enough to wipe away concerns even under a very optimistic scenario. We also evaluate effects of foreign workers on skill-specific wages in Japan and welfare consequences across heterogeneous individuals. A rapid rise in the relative size of high-skilled labor force in Japan will give strong downward pressure on skill premium and an arrival of foreign workers is shown to have large differential effects on skill prices and the trend of wage inequality, depending on their size and skill composition.

Japan leads all advanced economies in terms of aging and has the highest debt to GDP ratio. The public pension, medical and long-term care (LTC) expenditures are projected to far outpace revenues and create significant fiscal burdens. In this paper, we develop a detailed overlapping generations model that incorporates the social insurance programs in detail, use most recent estimates from Japanese micro data and government demographic projections to discipline the earnings and labor supply profiles of heterogeneous agents and their cohort shares, and simulate future paths of fiscal and macroeconomic indicators. Our numerical results suggest that absent any change in current policies, Japan will continue to run large pension, public health, LTC, and basic deficits and the debt to GDP ratio will continue to reach unprecedented highs, with interest payments on the debt becoming larger and larger. Although no single policy tool can address fiscal consolidation, a combination of policies is found to achieve sustainability; raise the retirement age to 67, cut pensions by 10%; raise copays of health and LTC insurances to 20%, and find policies to propel female employment and earnings to the levels of their male counterparts, and increase consumption tax rate to 15%. Under these changes, the debt to output ratio in 2050 would be lower than that in 2020.

We construct a transition analysis based on a general equilibrium life-cycle model to investigate the effects of aging, and we evaluate various policy alternatives designed to lessen the negative influence of aging. In particular, we analyze reforms of insurance benefits and tax financing tools that were recently the focus of a great amount of attention and debate in Japan because of the tense financial situation there. We show that although the potential reforms improve the welfare of future generations, the political implementation of such reforms is difficult because of the large welfare costs for the current population. Our analysis suggests that a gradual reform with an intergenerational redistribution will be more politically implementable than an immediate reform.

The labor force in Japan is projected to fall from 64 million in 2014 to 20 million in 2100, signaling unprecedented tax/transfer adjustments to achieve fiscal sustainability. In this paper, we develop a quantitative overlapping generations model to measure the impact of guest worker programs in Japan. Against a baseline general equilibrium transition in which the consumption tax adjusts to achieve fiscal sustainability, we compute alternative transitions with guest worker programs. Depending on the size and skill distribution of guest workers, these programs may mitigate Japan's fiscal imbalance problem with a relatively manageable increase in the consumption tax.

Japan is aging and has the highest government debt-to-output ratio among advanced economies. In this article, we build a micro data-based, large-scale overlapping generations model for Japan in which individuals differ in age, gender, employment type, income, and asset holdings, and incorporate the Japanese pension rules. Using existing pension law, current fiscal policy, and medium variants of demographic projections, we produce future paths for government expenditures and tax revenues, with implications for government debt and the public pension fund. Additional pension reform, a higher consumption tax, and higher female labor force participation help achieve fiscal stability.

In this paper we document the main features of the distributions of wages, earnings, consumption and wealth in Japan since the early 1980s using four main data sources; the Basic Survey on Wage Structure (BSWS), the Family Income and Expenditure Survey (FIES), the National Survey of Family Income and Expenditure (NSFIE) and the Japanese Panel Survey of Consumers (JPSC). We present an empirical analysis of inequality that specifically considers the path from individual wages and earnings, to household earnings, after-tax income, and finally consumption. We find that household earnings inequality rose substantially over this period. This rise is made up of two distinct episodes; from 1981 to 1996 all incomes rose, but they rose faster at higher percentiles; from 1996 to 2008 incomes above the 50th percentile remained flat but they fell at and below the 50th percentile. Inequality in disposable income and in consumption also rose over this period but to a lesser extent, suggesting taxes and transfers as well as insurance channels available to households helped to insulate household consumption from shocks to wages. We find the same pattern in inequality trends when we look over the life cycle of households as we do over time in the economy. Additionally we find that there are notable differences in the inequality trends for wages and hours between men and women over this period.

Using an OLG model with heterogeneous households, we investigate the relationship among income risk, macroeconomic and demographic changes, and economic inequality between 1980 and 2000 in Japan. By decomposing the primary factors in earnings and consumption inequality into macroeconomic variables and the demographic variable, we find that our model replicates the evolution of economic inequality in Japan. By performing counterfactual simulations, we demonstrate that two factors—changes in time-varying macroeconomic factors and the unexpected decline in the total factor productivity growth rate—played important roles in the increase in earnings and consumption inequality in the 1990s.

This paper investigates the welfare implications and political feasibility of social security reforms with a two-tier structure in Japan. We evaluate social security reforms from two points of view; (i) the ex-ante expected value of future generations, and (ii) whether current generations prefer reform to the status-quo system, which we call political feasibility. To evaluate the reforms, we use a large-scale overlapping generations model with idiosyncratic income risk and a two-tier structure. The first tier guarantees a basic pension and the second tier consists of the earnings-related part. Calibrating the parameters of the model to the Japanese economy, we compute the transition path and the two welfare criteria. We find that, given the two-tier structure in Japan, an increase in the basic pension and the abolition of the earnings-related part of the social security system improve the welfare of future generations, and ensures political feasibility when a consumption tax is the source of revenue.

This paper investigates the intergenerational sharing of shocks on the permanent income of new entry cohorts when prior-to-entry markets are missing. When Lucas trees are traded among generations, procyclical cohort-specific shocks are shared partially via the movement of asset prices; cohorts with lower endowments may benefit more from asset pricing dynamics than cohorts with higher endowments. Given a reasonable set of parameters concerning the Japanese labor market, the evaluated welfare loss ranges from 1% to 3% in terms of the certainty equivalence consumption level. The first-best outcome may be achieved by either a combination of subsidies and taxes or the introduction of prior-to-entry markets.

The present study investigate the relationship between the persistence of uninsurable income shocks and consumption inequality over a household's life cycle in Japan. Using a life cycle model with incomplete asset markets and calibrated parameters for the Japanese economy, we quantitatively show that moderate persistence of shocks generate a nonlinear consumption inequality profile over the life cycle. The moderate persistence of shocks well replicates the pattern of consumption inequality in Japan.

In contrast to many other countries, consumption inequalities in Japan are not constant over household age but increase from around middle age—a fact first highlighted by Ohtake and Saito (1998). Given this information, we examine whether this phenomenon is consistent with the standard precautionary saving model developed by Carroll (1997). Specifically, we investigate; (1) the degree of age dependence of idiosyncratic income risks; and (2) the importance of age dependence for the evolution of inequalities in consumption predicted by the household model of Carroll (1997). We find a strong age dependence of income risks, which creates a nonlinear age–variance profile of income, and the standard precautionary saving model is consistent with the observed consumption inequalities as long as we take the nonlinearity in age–variance profiles of income into account.