Time Preference and Macroeconomics

宏观经济的标准长期模型--新古典主义增长模型--假定了一种简单形式的家庭偏好，其中时间偏好的比率是恒定的。然而，最近的一些实验证据表明，家庭是短视的，因为短期内时间偏好率非常高，但未来某个时间段之间的时间偏好率要低得多。这个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，然后用跨国数据检验假设。对新古典增长模型进行了修正，以考虑非恒定的时间偏好率。如果家庭不能承诺未来的消费选择，如果效用是对数的，那么就会找到一个类似于新古典模型的标准结果的均衡。在这种解决方案中，时间偏好的有效率很高，但不变。尽管这种模式对制度设计和其他政策具有潜在的重要影响--因为家庭将受益于承诺未来消费的能力--但有一种感觉，即其结果在观察上等同于传统增长模式的结果。当框架扩展到允许部分承诺能力时，就会出现一些可检验的假设。对于更一般的效用函数，得到了稳态结果，并在等弹性效用的情况下得到了动态路径的一些性质。进一步的理论研究将评估均衡的唯一性。其他研究人员已经在类似的情况下发现了多种均衡，但只有在家庭的地平线是无限的情况下才能找到。在等弹性效用的情况下，过渡动力学的性质将被数值地计算出来，并将从理论中得到进一步的可检验的假设。这一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。之前关于经济增长决定因素的跨国实证工作将扩展到评估构成本研究理论部分的各种时间偏好分析的宏观经济意义。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。机构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环境的其他特点。文化方面将评估宗教、语言和种族方面对节俭、诚实倾向和努力工作意愿的可能影响。在每种情况下，要检验的假设是，解释变量对一组因变量产生联合影响，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。

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