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.     

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。     

A new interpretation for the precautionary saving motive: a note

This paper proposes a new interpretation for the precautionary saving motive: when future income is uncertain, agents increase saving in order to cause a reduction in the disutility due to uncertainty. Furthermore, the paper shows that the usual necessary and sufficient condition for precautionary saving is the condition ensuring this effect to occur and gives new insights into the relationship between risk aversion indexes and precautionary saving.      

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.      

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.      

经济转轨与城镇化进程中的居民消费行为特征——对1396户城镇家庭的实证分析

基于中国9个省1396户城镇家庭的面板数据,运用系统广义矩估计法对一个包括习惯形成和不确定性的欧拉方程进行估计以考察家庭消费是否跨时演进,研究结果表明,偏好的设定偏误是传统的生命周期——持久收入模型不能很好地诠释中国城镇家庭消费决策的一个原因,在解释消费决策的影响因素时假定偏好的跨时可分性会得出错误的结论,城镇居民消费偏好的跨时不可分性以及由收入和支出不确定性引发的预防性储蓄动机是导致居民消费倾向持续偏低的重要原因。     

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。     

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.     

转型经济中农户储蓄行为:中国农村的实证研究

本文运用大样本农户家庭调查资料 ,对决定中国农户家庭储蓄行为的影响因素进行了探索 ,从实际出发构建了一个具有较好解释力 ,且能对各种类型的变量均有所考虑的储蓄模型。研究发现 :(a)流动性约束、预防性储蓄动机以及工业化等对储蓄率的上升贡献相当大 ,且为正值 ;(b)在解释区域间储蓄率的差异时 ,文化是一个相当重要的因素 ;(c)家庭生命周期的“∪”型分布假说被拒绝 ,相反的“∩”型分布被发现 ;(d)当家庭财富与储蓄率的相关关系表现为负时 ,持久收入假说也被拒绝。     

Further Evidence from Aggregate Data on the Life-Cycle-Permanent-Income Model

We estimate the path of aggregate consumption implied by the permanent income hypothesis by allowing for parameter variation dictated by the theory. Our evidence, obtained by applying the Kalman filter to U.S. data for 1929–2001, supports the proposed generalisation and the fluctuations in the parameter estimates comply with a priori theoretical expectations.     

中国城市居民预防性储蓄及预防性动机强度:1999-2003

中国居民储蓄的超常增长近年来成为一个被普遍关注的问题 ,而居民储蓄动机更是成为人们关注的焦点。一个普遍的看法是 ,预防性储蓄动机在中国居民储蓄决策中起重要作用。本文从标准的消费者预期效用最大化模型出发 ,推导出收入不确定性条件下消费函数的显式解和衡量预防性动机强度的公式 ;然后用我国 3 5个大中城市1 999— 2 0 0 3年的数据进行计量分析 ,结果发现 3 5个大中城市的居民储蓄行为中的确存在预防性动机 ,但预防性动机并非如人们预期的那么强。在对该结果的可能原因进行分析后 ,本文给出了若干政策建议。