2025/09/26 by Dijk, Dylan, Cho, Haeran
#FOS: Computer and information sciences #Methodology (stat.ME)
paper · doi:10.48550/arxiv.2509.22235
We study the problem of modelling high-dimensional, heavy-tailed time series data via a factor-adjusted vector autoregressive (VAR) model, which simultaneously accounts for pervasive co-movements of the variables by a handful of factors, as well as their remaining interconnectedness using a sparse VAR model. To accommodate heavy tails, we adopt an element-wise truncation step followed by a two-stage estimation procedure for estimating the latent factors and the VAR parameter matrices. Assuming the existence of the (2 + 2ε)-th moment only for some ε∈ (0, 1), we derive the rates of estimation that make explicit the effect of heavy tails through ε. Simulation studies and an application in macroeconomics demonstrate the competitive performance of the proposed estimators.