Theta method for a unit root data‐generating process we:(a) derive new theoretical
formulations for the application of the method on multivariate time series;(b) investigate the
conditions for which the multivariate Theta method is expected to forecast better than the
univariate one;(c) evaluate through simulations the bivariate form of the method; and (d)
evaluate this latter model in real macroeconomic and financial time series. The study …