Each series follows a Markov chain with the serial dependence captured using copula-
based transition probabilities from the Poisson and the zero-inflated Poisson (ZIP) margins.
The copula theory was also used again to capture the dependence between the two series
using either the bivariate Gaussian or “t-copula” functions. Such a method provides a flexible
dependence structure that allows for positive and negative correlation, as well. In addition …