Constrained Inefficiency and Optimal Taxation with Uninsurable Risks

When individuals' labor and capital income are subject to uninsurable idiosyncratic risks, should capital and labor be taxed, and if so how? In a two‐period general equilibrium model with production, we derive a decomposition formula of the welfare effects of these taxes into insurance and distribution effects. This allows us to determine how the sign of the optimal taxes on capital and labor depend on the nature of the shocks and the degree of heterogeneity among consumers' income, as well as on the way in which the tax revenue is used to provide lump‐sum transfers to consumers. When shocks affect primarily labor income and heterogeneity is small, the optimal tax on capital is positive. However, in other cases a negative tax on capital is welfare‐improving.     

PRICE SEARCH,CONSUMPTION INEQUALITY AND EXPENDITURE INEQUALITY OVER THE LIFE ‐CYCLE

We differentiate consumption from expenditure by incorporating price search decision into an otherwise standard life‐cycle model. We first analytically show that, under very general conditions, poorer households search more and pay lower prices compared to wealthier ones. As a result, consumption inequality is smaller than expenditure inequality, and the gap between them increases over the life‐cycle. Next, using a plausibly calibrated model, we find that life‐cycle increase in consumption inequality is about 30% lower than the increase in expenditure inequality. Price search provides an insurance mechanism against income shocks and increases the welfare of a newborn by 3.9%.     

IDIOSYNCRATIC RISK,AGGREGATE RISK,AND THE WELFARE EFFECTS OF SOCIAL SECURITY

We ask whether a pay‐as‐you‐go financed social security system is welfare improving in an economy with idiosyncratic and aggregate risk. We show that the whole welfare benefit from insurance against both risks is greater than the sum of benefits from insurance against the isolated risks. One reason is the convexity of the welfare gain. The other reason is a direct risk interaction amplifying the utility losses from risk. Our quantitative evaluation shows that introducing a minimum pension leads to sizeable welfare gains, despite substantial crowding out. About 60% of these gains would be missing from summing up the isolated benefits.     

The tradeoff between social insurance and aggregate fluctuations

Government programs that insure individuals against idiosyncratic risks, such as unemployment insurance, attempt to offset shocks that are obscured by behavioral variables. The resultant moral hazard reduces the efficiency of the insurance. When this feature is examined in a dynamic setting, the variance and duration of aggregate income fluctuations may be intensified by insurance.     

When is market incompleteness irrelevant for the price of aggregate risk (and when is it not)?

In a standard incomplete markets model with a continuum of households that have constant relative risk aversion (CRRA) preferences, the absence of insurance markets for idiosyncratic labor income risk has no effect on the premium for aggregate risk if the distribution of idiosyncratic risk is independent of aggregate shocks and aggregate consumption growth is independent over time. In equilibrium, households only use the stock market to smooth consumption; the bond market is inoperative. Furthermore, the cross-sectional distributions of wealth and consumption are not affected by aggregate shocks. These results hold regardless of the persistence of idiosyncratic shocks, even when households face tight solvency constraints. A weaker irrelevance result survives when we allow for predictability in aggregate consumption growth.     

CAN HOUSEHOLDS AND WELFARE STATES MITIGATE RISING EARNINGS INSTABILITY?

We compare the evolution of earnings instability in Germany and the United Kingdom, two countries which stand for different types of welfare states. Deploying data from the German Socio‐Economic Panel (SOEP) and the British Household Panel Survey (BHPS), we estimate permanent and transitory variances of male income over the period 1984–2009 and 1991–2006, respectively. Studies in this literature generally use individual labor earnings. To uncover the role of welfare state and households in smoothening earnings shocks, we compute different income concepts ranging from gross earnings to net equivalent household income. We find evidence that the overall inequality of earnings in Germany and the United Kingdom has been rising throughout the period due to both higher permanent earnings inequality and higher earnings volatility. However, taking institutions of the welfare state and risk‐sharing households into account, we find that the volatility of net household income has remained fairly stable. Furthermore, redistribution and risk insurance provided by the welfare state is more pronounced in Germany than in the United Kingdom.     

On the persistence of income shocks over the life cycle: Evidence,theory, and implications

How does the persistence of earnings change over the life cycle? Do workers at different ages face the same variance of idiosyncratic earnings shocks? This paper proposes a novel specification for residual earnings that allows for an age profile in the persistence and variance of labor income shocks. We show that the statistical model is identified, and we estimate it using Panel Study of Income Dynamics data. We find that shocks to earnings are only moderately persistent (around 0.75) for young workers. Persistence rises with age, up to unity, until midway through life. The variance of persistent shocks exhibits a U-shaped profile over the life cycle (with a minimum of 0.01 and a maximum of 0.05). These results suggest that the standard specification in the literature (with age-invariant persistence and variance) cannot capture the earnings dynamics of young workers. We also argue that a calibrated job turnover model can account for these nonflat profiles. The key idea is that workers sort into better jobs and settle down as they age; in turn, magnitudes of wage growth rates decline, thereby decreasing the variance of shocks. Furthermore, the decline in job mobility results in higher persistence. Finally, we investigate the implications of age profiles for consumption–savings behavior. The welfare cost of idiosyncratic risk implied by the age-dependent income process is up to 1.6 percent of lifetime consumption lower compared with its age-invariant counterpart. This difference is mostly due to a higher degree of consumption insurance for young workers, for whom persistence is moderate. These results suggest that age profiles of persistence and variances should be taken into account when calibrating life-cycle models.     

Optimal age‐dependent income taxation in a dynamic extensive model: The case for negative participation tax on young people

We consider optimal age‐dependent income taxation in a dynamic model where the labor‐leisure choice is the extensive margin, each household faces idiosyncratic shocks to labor productivity and a pecuniary cost to work, and there is no insurance market against the shocks. We show that the well‐known property of the optimal participation tax rate in the static model continues to hold in our dynamic economy, that is, the participation tax rates for some income groups with low consumption are likely negative. In dynamic models, the optimal participation tax rate depends on age and on labor income. Our numerical simulations suggest that a negative participation tax should be restricted to young households.     

MEASURING THE IMPACT OF VALUING HEALTH INSURANCE ON LEVELS AND TRENDS IN INEQUALITY AND HOW THE AFFORDABLE CARE ACT OF 2010 COULD AFFECT THEM

A substantial part of the U.S. inequality literature focuses on yearly levels and trends in pre‐tax, post‐transfer cash income and its distribution over time and finds that median income appears to be stagnating, with income growth primarily coming at higher income levels. When we use data from the Current Population Survey for 1995–2008 and add the value of employer‐ and government‐provided health insurance coverage, not only does it increase the upward trend in the level of resources controlled by Americans, but also reduces the level of inequality in these resources and its upward trend. We then provide a highly stylized example of this broader income measure's value in capturing the impact of two key provisions of the Affordable Care Act of 2010—an expansion in Medicaid and the provision of subsidies to lower‐income families for purchasing private coverage on state‐run exchanges. Even though these incremental expansions build on existing systems of government‐provided health insurance, we find that the vast majority of the benefits would still accrue to the bottom three deciles of the income distribution when we include the value of employer‐ and government‐provided health insurance in our expanded yearly income measure. (JEL D31, H51, I14)     

POLICY UNCERTAINTY,ELECTORAL SECURITIES,AND REDISTRIBUTION*

This article investigates how uncertainty about the adoption of a redistribution policy affects political support for redistribution when individuals can trade policy‐contingent securities in the stock market. In equilibrium the support for redistribution is smaller than where no “policy‐insurance market” is available. This implies that in economies with well‐developed financial markets redistribution decreases with the level of participation in these markets and with income inequality. Furthermore, the existence of a policy‐insurance market may lead to a less equal distribution of income than where no insurance is available even if a majority of individuals are redistributing resources through private transfers.     

Social networks near and far: The role of bonding and bridging social capital for assets of the rural poor

With formal insurance and credit markets either absent or inaccessible to rural agents in most poor rural economies, social networks play a highly important role in mitigating the risks that agricultural households face. These kinds of informal insurance schemes are presumed to be most effective in the face of idiosyncratic risk. However, social mechanisms also exist in developing countries that may reduce locally correlated risk such as the adverse economic effects of climatic conditions that affect multiple residents in a village. This paper analyzes the role of localized (bonding) and of spatially dispersed (bridging) social capital in mitigating the impact of idiosyncratic and of locally correlated shocks on farm households’ livestock endowments. Using dynamic panel generalized method of moments (GMM) system estimation with seven‐period panel dataset of over 400 households, we find that bonding social capital is able to protect households’ livestock assets against idiosyncratic shocks, but bridging social capital does not play a role in mitigating the impact of correlated shocks. The results hold up to multiple robustness checks. A test of different hypotheses about the nature of these assets’ trajectories rejects the asset poverty trap hypothesis, and instead finds that livestock asset dynamics are characterized by a single stable equilibrium.     

HOUSE PRICES AND CONSUMPTION INEQUALITY

I characterize how house price shocks affect consumption inequality using a life cycle model of housing and nonhousing consumption with incomplete markets. I derive analytical expressions for the dynamics of inequalities and use these to analyze large house prices swings seen in the United Kingdom. I show that movements in consumption inequality were large, that they correspond with the theoretical predictions qualitatively, and that the model explains a large fraction of the movements quantitatively. I demonstrate the accuracy of this analysis using an extended model's full nonlinear solution. Finally, accounting for house price shocks alters estimates of labor–income risks using cross‐sectional data.     

Consumption smoothing in Russia

This paper uses panel data from rounds V–IX of the Russian Longitudinal Monitoring Survey (RLMS) to examine the extent to which households are able to protect their consumption from fluctuations in their income. It is found that consumption is only partially protected from idiosyncratic shocks to income with food consumption being better protected than non‐food consumption expenditures. This suggests that adjustments in non‐food expenditures may be an important component of the risk management tools of Russian households. The analysis also provides evidence on the extent and nature of the coping strategies adopted by households. It is demonstrated that households complement their self‐insurance strategies, of borrowing, adjusting their labour supply, and selling assets, with informal risk sharing arrangements with households within their community. An examination of the role of sample selection confirmed that these findings are quite robust to this potential source of bias. Furthermore, accounting for the role of measurement and imputation errors in the measure of household income revealed that OLS estimates may yield a misleading picture about the extent to which urban and rural households are insured from idiosyncratic income shocks. JEL classification: D1, R2, P5.     

Monetary and fiscal policies in a heterogeneous‐agent economy

We study the effects of long‐run inflation and income taxation in an economy where households face uninsurable idiosyncratic risks. We construct a tractable competitive‐search framework that generates dispersion of prices, income and wealth. We analytically characterize the stationary equilibrium and the policy effects on individual choices. Quantitative analysis finds that monetary and fiscal policies have distinct effects on macro aggregates, such as output, savings and wealth, income and consumption inequalities. There is a hump‐shaped relationship between welfare and the respective policies. Overall, welfare is maximized by a deviation from the Friedman rule, paired with distortionary income taxation.     

Optimal monetary policy: distribution efficiency versus production efficiency

This paper investigates the trade‐off between distribution effect and production effect of monetary policy when there exist unobservable idiosyncratic liquidity shocks. In the absence of risk‐sharing arrangements such as a credit market, monetary policy serves to provide ex post insurance to smooth consumption. Specifically, issuing interest‐bearing bonds restores credit transactions on money through bond‐money exchanges. Such a policy has a positive distribution effect, but the resulting inflation hampers production efficiency. It is demonstrated that the trade‐off between distribution efficiency gain and production efficiency loss would result in net welfare enhancement if consumers are relative‐risk‐averse enough.     

Effects of Aspirations and Habits on the Distribution of Wealth

We analyze how the introduction of habits and aspirations affects the distribution of wealth when the labor productivity of individuals is subject to idiosyncratic shocks and when bequests arise from a joy‐of‐giving motive. In the presence of either bequests or aspirations, labor income shocks are transmitted intergenerationally, and this transmission, together with contemporaneous shocks, determines the distribution of wealth. We show that the introduction of aspirations (habits) decreases (increases) the average wealth, and increases (decreases) both its intragenerational variability and the degree of intergenerational mobility. Therefore, a distinction between aspirations and habits is relevant because they involve different implications for the distribution of wealth.     

Automation and inequality with taxes and transfers

Declines in low-skill labour shares are reviewed, and a stylised model is constructed to examine their determinants and future implications. A retrospective analysis of US shocks suggests that technological change has contributed more to raising income inequality and the wealth to GDP ratio than other changes. An anticipated future twist away from low-skill labour toward the capital, combined with population growth, risks high unemployment rates. Productivity growth at twice the pace since 1990 limits this, though inequality persists. Analysis shows that a generalisation of the US ‘earned income tax credit’ system with consumption tax outperforms alternatives of the ‘universal basic income’.     

Multi-dimensional risk and the cost of business cycles

This paper analyzes the welfare costs of business cycles when workers face uninsurable idiosyncratic labor income risk. In accordance with the previous literature, this paper decomposes labor income risk into an aggregate and an idiosyncratic component, but in contrast to the previous literature, this paper allows for multiple sources of idiosyncratic labor income risk. Using the multi-dimensional approach to idiosyncratic risk, this paper provides a general characterization of the welfare cost of business cycles when preferences and the (marginal) process of individual labor income in the economy with business cycles are given. The general analysis shows that the introduction of multiple sources of idiosyncratic risk never decreases the cost of business cycles, and strictly increases it if there are cyclical fluctuations across the different sources of risk. This paper also provides a quantitative analysis based on a version of the model that is calibrated to match US labor market data. The quantitative analysis suggests that realistic variations across two particular dimensions of idiosyncratic labor income risk increase the welfare cost of business cycles by a substantial amount.     

Redistributive innovation policy,inequality, and efficiency

We examine the efficiency and distributional effects of regressive and progressive public R&D policies that target high‐tech and low‐tech sectors using a heterogenous‐agent growth model with in‐house R&D and incomplete capital markets. We find that such policies have important implications for efficiency and inequality. A regressive public R&D investment financed by income tax could boost growth and welfare via a positive effect on individual savings and effort. It could, however, also lower growth and welfare via its effect on the efficiency–inequality trade‐off. Thus, the relationship between public R&D spending and welfare is hump‐shaped, admitting an optimal degree of regressivity in public R&D spending. Using our baseline model, and the US state‐level GDP data, we derive the degree of regressiveness of public R&D investment in US states. We find that US states are more regressive in their R&D investment than the optimal regressiveness implied by our growth model.     

Risk coping and starvation in rural China

We use a 3-year panel from two poor provinces in Southern China to examine the nature of risks to which rural households are exposed and their ability to insure calorie consumption and spending of total consumption against idiosyncratic shocks to their income. We find that idiosyncratic risks are indeed the main source of income variation in the sample, consumption is better insured than total spending. Unlike total spending where full insurance is rejected in most cases, calorie intake is completely insured for both land-rich and land-poor households in both provinces. Access to even modest amounts of land significantly enhances households’ ability to guard against total spending. Land-rich households are much better insured against total spending than land-poor households. The results are robust across model specifications although Generalized Method of Moments (GMM) estimations increase the magnitude of difference in total spending between the land-rich and the land-poor. Policies targeting poverty reduction and improving land use rights and land access to the poor could potentially improve the overall risk sharing ability of the rural poor.