Regularized estimation of high‐dimensional vector autoregressions with weakly dependent innovations

Autor: Marcelo C. Medeiros, Ricardo Masini, Eduardo F. Mendes
Rok vydání: 2021
Předmět:
Zdroj: Journal of Time Series Analysis. 43:532-557
ISSN: 1467-9892
0143-9782
DOI: 10.1111/jtsa.12627
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: OpenAIRE