Regularized Estimation of High-Dimensional Vector AutoRegressions with Weakly Dependent Innovations

Autor: Masini, Ricardo P., Medeiros, Marcelo C., Mendes, Eduardo F.
Rok vydání: 2019
Předmět:
Druh dokumentu: Working Paper
Popis: There has been considerable advance in understanding the properties of sparse regularization procedures in high-dimensional models. In time series context, it is mostly restricted to Gaussian autoregressions or mixing sequences. We study oracle properties of LASSO estimation of weakly sparse vector-autoregressive models with heavy tailed, weakly dependent innovations with virtually no assumption on the conditional heteroskedasticity. In contrast to current literature, our innovation process satisfy an $L^1$ mixingale type condition on the centered conditional covariance matrices. This condition covers $L^1$-NED sequences and strong ($\alpha$-) mixing sequences as particular examples.
Databáze: arXiv