论文标题
结合结合矢量自回归模型中的收缩和稀疏性
Combining Shrinkage and Sparsity in Conjugate Vector Autoregressive Models
论文作者
论文摘要
共轭先验允许在大维矢量自回旋(VAR)模型中快速推断,但同时引入了以下限制:每个方程都具有相同的解释变量集。本文提出了一种直接的方法,即对偶联贝叶斯VAR的后验估计,以有效地执行方程特定的协变量选择。与仅使用收缩的现有技术相比,我们的方法结合了VAR系数和误差差异协方差矩阵的收缩和稀疏性,大大降低了较大维度的估计不确定性,同时保持计算障碍性。我们通过两种应用来说明我们的方法。第一个应用程序使用综合数据来研究模型在不同数据生成过程中的属性,第二个应用程序分析了美国数据预测练习中的稀疏性收益。
Conjugate priors allow for fast inference in large dimensional vector autoregressive (VAR) models but, at the same time, introduce the restriction that each equation features the same set of explanatory variables. This paper proposes a straightforward means of post-processing posterior estimates of a conjugate Bayesian VAR to effectively perform equation-specific covariate selection. Compared to existing techniques using shrinkage alone, our approach combines shrinkage and sparsity in both the VAR coefficients and the error variance-covariance matrices, greatly reducing estimation uncertainty in large dimensions while maintaining computational tractability. We illustrate our approach by means of two applications. The first application uses synthetic data to investigate the properties of the model across different data-generating processes, the second application analyzes the predictive gains from sparsification in a forecasting exercise for US data.