Analysis of co-explosive processes

A vector autoregressive model allowing for unit roots as well as explosive characteristic roots is developed. The Granger-Johansen representation shows that this results in processes with two common features: a random walk and an explosively growing process. Co-integrating and co-explosive vectors can be found which eliminate these common factors. Likelihood ratio tests for linear restrictions on the co-explosive vectors are derived. As an empirical illustration the method is applied to data from the extreme Yugoslavian hyper-inflation of the 1990s.