Spatio-temporal Modeling of Count Data

We introduce parsimonious parameterisations for multivariate autoregressive count time series models for spatio-temporal data, including possible regressions on covariates. The number of parameters is reduced by specifying spatial neighbourhood structures for possibly huge matrices that take into account spatio-temporal dependencies. Consistency and asymptotic normality of the parameter estimators are obtained under mild assumptions by employing quasi-maximum likelihood methodology. This is used to obtain an asymptotic Wald test for testing the significance of individual or group effects. Several simulations and two data examples support and illustrate the methods proposed in this paper.