Modeling Count Data
Anoop Kumar Chaturvedi · Journal of the Royal Statistical Society Series A (Statistics in Society) · 2015
Modelling Count Data is a well-organized entry level book mainly written for applied researchers with little formal theoretical background in statistics who need to analyse count data. The book provides a treatment of various statistical models for count data; their analysis, evaluation, interpretation and limitations. Starting with the basic structure of statistical count data models the book covers treatment of Poisson regression models and the testing and remedies to resolve overdispersion; the negative binomial model is specifically covered and generalizations of Poisson regression models such as Poisson and inverse Gaussian regression; zero-truncated and zero-inflated models as well as underdispersed models are covered. Recent developments in count data models such as handling highly unbalanced count data, censored count data, mixture models, generalized additive models, models for longitudinal data and Bayesian count models are also covered. However, I feel that covering all these modern developments in a single chapter (Chapter Nine) and discussing them without much background make it difficult for the intended (non-statistical specialists) to understand. The book uses several applied examples to illustrate and motivate different count models; worked examples are given with Stata, R and SAS. Code and solutions are provided along with a discussion of the results. The book assumes that readers will have basic knowledge of such software. Thoroughly worked examples with software code, several of them devoted to applying alternative count models to the same data set, provide a basic guide for model selection among competing models. The chapters are well structured, starting with points of discussion and ending with a brief summary. Where required, section themes are summarized. Also, the formula used, abbreviations used and examples used are summarized in tabular form. In brief it is a remarkable book and can be used as a practical guide for introducing count data analysis.