WHY DON'T AMERICANS SAVE ENOUGH FOR RETIREMENT?

美国消费者为退休储蓄不足——这是他们自己承认的，也有很多其他的衡量标准——而社会科学家也没有什么模型可以解释这个问题。本研究将通过建立具有心理学微观基础的经济模型来分析储蓄不足问题。本研究将使用双曲折现函数来模拟自我控制问题。双曲型消费者经历了一种矛盾，即他们对患者行为的长期偏好与对即时满足的短期渴望之间的矛盾。本研究将使用一种新的前向归纳启发式方法来模拟金融复杂程度有限的消费者的决策。该项目将开发一个消费者行为的正式数学模型，该模型集成了自我控制问题和有限理性的影响。这个决策模型将嵌入到一个模拟经济中，这个模拟经济模仿了美国家庭所面临的丰富的储蓄选择和激励。该模型将从四个方面进行分析。首先，对仿真模型进行实证检验。其次，该模型将用于评估现有退休工具的有效性，如社会保障、401(k)计划、个人退休账户和私人固定收益养老金计划。第三，研究将衡量储蓄不足问题的严重程度。第四，该研究将为设计比现有退休工具更有效的新储蓄机构提供模拟框架。

U.S. consumers are undersaving for retirement - by their own admission and by many other measures - and social scientists have few models that can explain this problem. The proposed research will analyze the undersaving problem by developing economic models with psychological microfoundations. The research will use the hyperbolic discount function to model self-control problems. Hyperbolic consumers experience a contradiction between their long-run preference for patient behavior and their short-run desire for instantaneous gratification. The research will use a new forward induction heuristic to model the decision-making of consumers with limited financial sophistication. The project will develop a formal mathematical model of consumer behavior which integrates the effects of self- control problems and bounded rationality. This decision-making model will be embedded in a simulated economy which mimics the rich set of saving choices and incentives faced by U.S. households. The model will be analyzed in four ways. First, the simulation model will be empirically tested. Second, the model will be used to evaluate the efficacy of existing retirement instruments like social security, 401(k)'s, IRA's, and private defined-benefit pension plans. Third, the research will measure the magnitude of the undersaving problem. Fourth, the research will provide a simulation framework for designing new savings institutions which are more effective than existing retirement instruments.