Time Preference and Macroeconomics

宏观经济学的标准长期模型--新古典增长模型--假设了一种简单的家庭偏好形式，其中时间偏好率是恒定的。然而，最近的一些实验证据表明，家庭是短视的，在这个意义上，时间偏好率在短期内非常高，但在未来的某个时间之前的日期之间要低得多。本项目将评估这种形式的偏好对可观察到的宏观经济行为的理论影响，然后在跨国数据上检验假设。 对新古典增长模型进行了修正，使其考虑了时间偏好率的非恒定性。如果家庭不能承诺未来的消费选择，如果效用是对数的，那么就会发现一个均衡，类似于新古典模型的标准结果。在该解中，时间偏好的有效率很高，但不变。尽管这一模型对制度设计和其他政策具有潜在的重要意义--因为家庭将受益于承诺未来消费的能力--但在某种意义上，其结果在观测上与传统增长模型的结果是等价的。当框架扩展到允许部分承诺能力，然后出现一些可检验的假设。稳态结果得到更一般的效用函数，和一些性质的动态路径的情况下的等弹性效用。 进一步的理论研究将评估均衡的唯一性。其他研究者在类似的背景下也发现了均衡的多重性，但只有当家庭的视野是无限的时候。对于等弹性效用的情况，过渡动力学的性质将用数值计算出来，并从理论中推导出进一步的可检验的假设。该理论还将与现有的将人口增长和技术进步内生化的分析联系起来。 以前的跨国实证工作的经济增长的决定因素将被扩展到评估的宏观经济意义的时间偏好分析，形成本研究的理论部分。分析将考虑影响人们作出和执行承诺的能力的体制和文化因素。体制方面将考虑法治和政治稳定的措施以及影响人们组织金融市场和订立合同及其他市场关系的能力的法律的环境的其他特点。文化方面将评估宗教、语言和种族等方面对节俭、诚实倾向和努力工作意愿的可能影响。在每一种情况下，要检验的假设是，解释变量对一组因变量具有联合影响，这些因变量包括经济增长率、储蓄率、金融市场发展程度、生育率决定和人力资本投资强度 1/3 + 1/4

The standard long run model of the macroeconomy-the neoclassical growth model- assumes a simple form of household preferences in which the rate of time preference is constant. However, some recent experimental evidence suggests that households are myopic in the sense that rates of time preference are very high over the near term but much lower between dates advanced some time in the future. This project will assess the theoretical implications of this form of preferences for observable macroeconomic behavior and then test the hypotheses on cross country data. The neoclassical growth model is modified to allow for a non constant rate of time preference. If the household cannot commit future choices of consumption and if utility is logarithmic, then an equilibrium is found that resembles the standard results of the neoclassical model. In this solution, the effective rate of time preference is high, but constant. Although this model has potentially important implications for institutional design and other policies- because households would benefit from an ability to commit future consumption-there is a sense in which the results are observationally equivalent to those of the conventional growth model. When the framework is extended to allow for partial commitment ability, then some testable hypotheses emerge. Steady state results are obtained for more general utility functions, and some properties of dynamic paths are worked out for the case of isoelastic utility. Further theoretical research will assess the uniqueness of the equilibria. Multiplicity of equilibria have been found in analogous contexts by other researchers but only when the household's horizon is infinite. The properties of the transitional dynamics will be worked out numerically for the case of isoelastic utility, and further testable hypotheses will be derived from the theory. The theory will also be linked with existing analyses that endogenize population growth and technological progress. Previous cross country empirical work on the determinants of economic growth will be extended to evaluate the macroeconomic significance of the kinds of time preference analysis that form the theoretical part of this research. The analysis will consider institutional and cultural elements that affect people's ability to make and enforce commitments. The institutional side will consider measures of the rule of law and political stability and other features of the legal environment that affect people's ability to organize financial markets and enter into contracts and other market relationships. The cultural side will assess aspects of religion, language, and ethnicity as possible influences on thrift, a propensity for honesty, and a willingness to work hard. In each case, the hypothesis to be tested is that the explanatory variables have joint influences across a group of dependent variables, including the rate of economic growth, the saving rate, the extent of financial market development, fertility decisions, and the intensity of investment in human capital ½ñ+¼^úá¼