Optimal saving in the presence of two risks

We examine optimal saving in the presence of two small risks: income risk and a background risk. First, we compute the necessary and sufficient condition for a positive precautionary saving, showing that it depends on two terms capturing respectively the direct effect of income risk and the interaction between the two risks. Second, we examine the necessary and sufficient condition for a positive extra-saving due to the contemporaneous presence of the two risks. We show that this condition also depends on a term capturing the direct effect of background risk and that it can hold independently of the previous one.      

Optimal Taxation in the Presence of Black Markets

Received November 21, 2000; revised version received May 19, 2001     

Optimal Factor Income Taxation in the Presence of Unemployment

According to conventional wisdom internationally mobile capital should not be taxed or should be taxed at a lower rate than labour. An important underlying assumption behind this view is that there are no market imperfections, in particular that labour markets clear competitively. At least for Europe, which has been suffering from high unemployment for a long time, this assumption does not seem appropriate. This paper studies the optimal factor taxation in the presence of unemployment which results from the union-firm wage bargaining both with optimal and restricted profit taxation when capital is internationally mobile and labour immobile. In setting tax rates the government is assumed to behave as a Stackelberg leader towards the private sector playing a Nash game. The main conclusion is that in the presence of unemployment, the conventional wisdom turns on its head; capital should generally be taxed at a higher rate than labour.     

Precautionary saving in the presence of other risks: a comment

Courbage and Rey (Econ Theory 32:417–424 2007) analyse precautionary saving in the presence of a background risk under specific sets of assumptions on the form of income risk and background risk. Three cases are examined: the case of independent risks, the case of Bernoulli-distributed random variables and the case of risk first-degree stochastic. For each of these cases Courbage and Rey compute the specific sets of conditions related to precautionary saving. This comment shows that some of their conclusions are partially incorrect.      

中国居民储蓄率的决定因素——基于1995-2005年省际动态面板数据的分析

文章运用1995-2005年省际动态面板数据研究了城镇与农村居民储蓄率的决定因素,并检验了凯恩斯绝对收入理论与永久收入假说(生命周期理论)对中国的适应性。计量结果表明:城镇样本较好地支持了永久收入假说(生命周期理论),农村样本则较好地支持了凯恩斯理论。长期收入增长率是居民储蓄率的基本决定因素,高增长是高储蓄的主要原因。另外,居民储蓄的行为模式、人口年龄结构、社会保障制度、不确定性、信贷约束以及地区差异都是居民储蓄率的重要决定因素,但这些因素对城镇与农村居民储蓄率的影响存在显著差异。     

Self-insurance in a life-cycle model of labour supply and savings

This paper analyses the incentives to work and to save over the life cycle in the presence of incomplete markets. In a calibrated, partial equilibrium model, flexibility in hours worked changes asset age-profiles: borrowing when young is greater and saving when middle-aged is greater than when labour supply is fixed. Uncertainty causes individuals to work longer hours and to consume less when young. With flexibility over hours, accumulating precautionary assets incurs less of a utility cost and so the level of saving is greater. Further, allowing for flexibility and uncertainty means simulated hours of work and consumption more closely match the age profiles in the data.     

The impact of the correlation between health expenditure and survival probability on the demand for insurance

This paper studies the effects of health shocks on the demand for health insurance and annuities, along with precautionary saving in a dynamic life-cycle model. I argue that when the health shock can simultaneously increase health expenses and reduce longevity, rational agents would neither fully insure their uncertain health expenses nor fully annuitize their wealth because the correlation between health expenses and longevity provides a self-insurance channel for both uncertainties. That is, when the agent is hit by a health shock (which simultaneously increases health expenses and reduces longevity), she can use the resources originally saved for consumption in the reduced period of life to pay for the increased health expenses. Since the two uncertainties partially offset each other, the precautionary saving generated in the model should be smaller than in a standard model without the correlation between health expenses and longevity. In a quantitative life-cycle model calibrated using the Medical Expenditure Panel Survey dataset, I find that the health expenses are highly correlated with the survival probabilities, and this correlation significantly reduces the demand for actuarially fair health insurance, while its impact on the demand for annuities and precautionary saving is relatively small.     

Optimal Taxation of Risky Human Capital*

In a two‐period life‐cycle model with ex ante homogeneous households, earnings risk, and a general earnings function, we derive the optimal linear labor tax rate and optimal linear education subsidies. The optimal income tax trades off social insurance against incentives to work. Education subsidies are not used for social insurance, but they are only targeted at offsetting the distortions of the labor tax and internalizing a fiscal externality. Both optimal education subsidies and tax rates increase if labor and education are more complementary, because education subsidies indirectly lower labor tax distortions by stimulating labor supply. Optimal education subsidies (taxes) also correct non‐tax distortions arising from missing insurance markets. Education subsidies internalize a positive (negative) fiscal externality if there is underinvestment (overinvestment) in education because of risk. Education policy unambiguously allows for more social insurance if education is a risky activity. However, if education hedges against labor‐market risk, optimal tax rates could be lower than in the case without education subsidies.     

Precautionary saving in the presence of other risks

Does the sign of the third derivative of the utility function with respect to wealth still govern precautionary saving motives in the presence of a background risk? This article shows that some other properties of the utility function have also to be considered depending on the serial correlation existing between the background risk and the future income risk.     

劳动要素报酬、人口结构与中国居民储蓄

以动态一般均衡模型为出发点,分析劳动要素报酬、人口结构对居民储蓄率的影响,并运用中国1978～2009年的数据对劳动要素报酬、老人赡养比、儿童抚养比与中国居民储蓄率进行实证检验。研究发现,市场经济转型以来的劳动要素报酬高速增长、老人赡养比上升以及儿童抚养比的下降导致中国储蓄率不断升高,在此基础上给出相应的政策建议。     

Commodity Taxation and the Effects of Entry: A Case of Variety Preferences

We study the relationship between commodity taxation and the effect of entry with imperfect competition. We develop a simple general equilibrium model with imperfect competition in which consumers have variety preferences. As a result, we see that introducing specific taxes increases social welfare. Furthermore, we show that the optimal tax rule is contrary to the inverse elasticity rule.Acknowledgement We wish to thank two anonymous referees for their helpful comments.     

Optimal Environmental Management in the Presence of Irreversibilities

We consider an environment of a fixed size that can be converted to another use. This conversion can be made in steps, but it is irreversible. The future benefits (per unit) from the original use, and from the alternative use, follow a diffusion process. For a fairly general case, we show that the value function must be the unique (viscosity) solution to the associated Hamilton-Jacobi-Bellman equation. We also exhibit several properties of the solution for the case of constant relative risk aversion between 0 and 1, and a log-linear diffusion for the benefits. Journal of Economic Literature Classification Numbers: C61, D90, Q30.     

On the utility premium of Friedman and Savage

We re-examine the utility premium of Friedman–Savage [Friedman, Milton and Savage, Leonard J., “The Utility Analysis of Choices Involving Risk.” Journal of Political Economy 56, 1948, pp. 279–304.]. This measure is useful in understanding risky choices. For instance its reaction to an increased wealth equates to a precautionary demand for saving. We also analyze its two components.     

构建和谐社会的税收政策研究--以公平收入分配为视角

中国居民收入差距的现状令人堪忧,应遵循“公平优先、兼顾效率”的新财税理念,构建公平居民收入分配的税收对策:转变财税理念,调整税收政策和制度,推进个人所得税征管制度改革。     

Estimating a Dynamic Model of Household Choices in the Presence of Income Taxation

The purpose of the article is to study the incentive and distributional consequences of income taxation. The article analyzes tax changes in a dynamic setting. The framework is estimated under a set of different identifying assumptions using parametric, nonparametric, and semiparametric techniques. The empirical results focus on tax reforms in Germany in the 1980s. The article shows that these reforms did not significantly lower effective tax rates. The findings also suggest that estimated elasticities for male labor supply are small, ranging between 0.02 and 0.2.     

On the Optimal Taxation in a Growth Model of the Mixed Economy

Previous studies of second‐best taxation have shown that capital income shall not be taxed in the long run for some cases where individuals have infinite lives and a utility function of special form. The present paper improves upon this conclusion in two respects: first, the utility function may be of more general form, and second, zero capital income tax is required for the entire period, which does not depend on whether the individual's horizon is infinite or finite. Furthermore, we also show that the optimal tax rate on capital income should tend to zero in the long run if the first‐best optimum is attainable.     

On the Flexibility of Optimal Policies for Green Design

Several recent papers show that different combinations of taxes and subsidies can achieve the social optimum for green design and household waste management when there are various market failures. This note shows that such policy flexibility exists only if all relevant actions by individual agents can be properly targeted by economic instruments. If the household can make a private effort to reduce waste, then an optimal policy is shown to be a unique combination of given economic instruments.     

Commodity exports and labour productivity in the long run

Empirical analysis of dynamic panel data models shows that dependence on exports of ores and metals is associated with lower labour productivity. For other commodity groups, there is no statistically significant effect.     

Optimal balanced growth in a general multi-sector endogenous growth model with constant returns

I will study a multi-sector endogenous growth model with general constant returns to scale technologies and demonstrate the existence, uniqueness and the saddle-path stability of the balanced growth equilibrium. I will first demonstrate the existence of a balanced growth equilibrium, by showing that the balanced growth rate associated with the balanced growth equilibrium is solely determined by solving a Frobenius root problem of the price equations derived from the Euler equations and the property of the nonsubstitution theorem. Then I will show the saddle-path stability of the balanced growth equilibrium without any capital intensity conditions, which is a generalized property proved in the two-sector endogenous growth models by de Guevara et al. (J Econ Dyn Control 21, 115–143, 1997), Bond et al. (J Econ Theory 68, 149–173 1996) and Mino (Int Eco Rev 37, 227–251 1996). The theorem clearly implies that the balanced growth equilibrium has a transition path in the neighborhood of the balanced growth equilibrium. The paper was presented at the conferences “Irregular Growth: Beyond Balanced Growth” held on June 19–21, 2003 in Paris and “Economic Growth and Distribution: On the Nature and Causes of the Wealth of Nations” held on June 16–18, 2004 in Lucca, Italy. From the discussion with Alain Venditti at CNRS-GREQAM, Gerhard Sorger at University of Vienna and the conference participants, I have been benefited much by writing this paper. Especially Alain Venditte had given me a chance to take a look at his unpublished paper titled ” Indeterminacy and the Role of Factor Substitutability” jointly written with Kazuo Nishimura at Kyoto University and published in Macroeconomic Dynamics, Vol. 8. The author also would like to thank an anonymous referee for useful suggestions.     

Optimal Stabilization Policy in the Presence of Learning by Doing

This paper analyses the optimal stabilization policy when growth is driven by learning by doing. If benefits of learning by doing are not fully internalized, the optimal policy is to tax labor during expansions and to subsidize it during recessions. The long-term impact of this policy depends critically on initial conditions: If stabilization starts during an expansion, it has a positive effect on long-term production. When stabilization starts during a recession, its long-term effect is negative. The paper makes a methodological contribution in its analytical derivation of the optimal policy along the transition path as well as in the steady state.