中文摘要：

在Dynan预防性储蓄模型的基础上，引入流动性约束和消费习惯等因素，利用1995－2012年全国城镇居民按收入阶层划分的调查数据，按照不同收入阶层居民的异质性对其进行再分组，构造收入组间动态面板，运用随机系数模型对不同收入阶层的城镇居民家庭预防性储蓄行为进行实证检验。结果表明，低收入群体的消费和储蓄行为主要受到流动性约束和不确定性的共同影响；中等收入群体对未来不确定性较敏感，具有较强的预防性储蓄动机；高收入群体面临不确定性时的预防性储蓄动机随收入水平的提高而降低。实际利率和消费习惯对各收入阶层城镇居民的消费行为影响程度都相对较小。

英文摘要：

Based on Dynan＇s precautionary saving model with the introduction of liquidity constraints and consumption habits, using survey data of national urban residents of different income groups from 1995 to 2012, and re-grouping by the heterogeneity of different income segments,this paper provides dynamic panel data among different income groups to make an empirical analysis on influencing factors of precautionary saving behavior of urban households divided by income groups in a random coefficient model. It shows that consumption and saving behavior of low-income groups is mainly effected by uncertainty and liquidity constraints. In order to deal with the uncertainty of future, middle-income groups tend to have a strong precautionary saving motive. High-income groups have a reducing precautionary saving motive for uncertainty with increasing income levels. In addition, the impact of real interest rate and habits formation on every income group is relatively small.