UNCERTAIN FUTURES: STOCHASTIC FORECASTS/DECISION MAKING

该项目的长期目标是扩展、开发和应用 进行随机人口预测的方法和使用这些方法的方法 预测决策和社会经济分析。工作提出的 这里有以下具体目标。 1. Lee和Tuljapurkar的随机方法推广到 人口泛函的概率分布;人口分布的投影 社会保障税收负担和转移支付等数量; 敏感性分析。 2.生命率的替代模型：多个主成分 捕捉死亡率变化的复杂性;预测的比较 Lee-Carter和McNown-Rogers模型的性能， 人口预测.参数的改进估计程序的使用 和标准误差;捕捉长期趋势的状态空间技术 和（或）周期;探讨生育率模型， Easterlin和Lee反馈;非线性时间序列技术的应用 分析以寻找生育率时间序列中非线性的证据; 估计非线性模型，从而发现使用非线性版本的 卡尔曼滤波器 3.按年龄分列的汇总分析： 增长率与人口结构的不确定性 和人口泛函;这种分解与 预测准确性的事后评估。 4.人口预测情况下的决策方法 不确定性，检查：（1）在上下文中的最优性和风险规避 不同的目标函数和（2）OASDI信任的动态 基金考虑风险的替代措施。

The long-term goals of this project are to extend, develop, and apply methods for making stochastic demographic forecasts and for using these forecasts in decision making and socioeconomic analysis. The work proposed here has the following specific goals. 1. Extensions of the stochastic method of Lee and Tuljapurkar to probability distributions of population functionals; projections of quantities such as the social security tax burden and transfers; and sensitivity analyses. 2. Alternative models for vital rates: multiple principal components to capture complexity of mortality change; comparison of the forecasting performance of the Lee-Carter and McNown-Rogers models in terms of population forecasts; use of improved estimation procedures for parameters and standard errors; state-space techniques to capture long-term trends and/or cycles; exploration of models of fertility that incorporate Easterlin and Lee feedbacks; use of techniques of nonlinear time-series analysis to look for evidence of nonlinearity in fertility time series; estimation of nonlinear models so discovered using nonlinear versions of the Kalman filter. 3. Analyses of aggregation by age: multigenerational decomposition of uncertainty due to rates vis-a-vis population structure for growth rate and for population functionals; the relationship of such decompositions to ex post evaluations of forecast accuracy. 4. Methods for decision making in the presence of demographic forecast uncertainties, examining: (1) optimality and risk aversion in the context of different objective functions and (2) the dynamics of the OASDI trust fund considering alternative measures of risk.