Two negative binomial mixed models with different dispersion specifications were compared for analysis of dairy reproduction count data. The first model was developed previously and had heterogeneous overdispersion in an associated logarithmic scale, assigning greater uncertainty to observations with smaller conditional expectations. The second model postulated homogeneous overdispersion across...

Abstract When dealing with time series outlying and atypical data, a commonly used approach is to develop models based on heavy-tailed distributions. The literature coping continuous-valued extreme observations well explored. However, current modelling integer-valued data heavy-tailedness less considered. state of the art research this topic presented by Gorgi (J R Stat Soc Ser B (Stat Methodol...