论文标题
高维动态随机模型表示
High-Dimensional Dynamic Stochastic Model Representation
论文作者
论文摘要
我们提出了一种可扩展的方法,用于计算非线性,高维动态随机经济模型的全球解决方案。首先,在时间迭代框架内,我们使用自适应,高维模型表示方案近似经济政策功能,并结合自适应稀疏网格,以应对维度诅咒的无处不在挑战。此外,由于仅在最需要的地方添加网格点,即在具有陡峭梯度的区域或无分量性的区域,因此各个组件函数内的适应性会增加稀疏性。其次,我们引入了插值计算内核的性能矢量化方案。第三,该算法是混合的,并同时利用分布式和共享记忆体系结构。我们观察到对最先进的技术的巨大加速,并且在瑞士国家超级计算中心的Cray XC $ 50 $系统的计算节点至少缩小至少$ 1,000 $。最后,为了证明我们的方法的广泛适用性,我们将全球解决方案计算为高维的国际真实商业周期模型的两个变体,最高$ 300 $连续的状态变量。此外,我们强调了该框架的互补优势,该框架可以对模型复杂性进行先验分析。
We propose a scalable method for computing global solutions of nonlinear, high-dimensional dynamic stochastic economic models. First, within a time iteration framework, we approximate economic policy functions using an adaptive, high-dimensional model representation scheme, combined with adaptive sparse grids to address the ubiquitous challenge of the curse of dimensionality. Moreover, the adaptivity within the individual component functions increases sparsity since grid points are added only where they are most needed, that is, in regions with steep gradients or at nondifferentiabilities. Second, we introduce a performant vectorization scheme for the interpolation compute kernel. Third, the algorithm is hybrid parallelized, leveraging both distributed- and shared-memory architectures. We observe significant speedups over the state-of-the-art techniques, and almost ideal strong scaling up to at least $1,000$ compute nodes of a Cray XC$50$ system at the Swiss National Supercomputing Center. Finally, to demonstrate our method's broad applicability, we compute global solutions to two variates of a high-dimensional international real business cycle model up to $300$ continuous state variables. In addition, we highlight a complementary advantage of the framework, which allows for a priori analysis of the model complexity.