%0 Journal Article %T An Exceptional Generalization of the Poisson Distribution %A Per-Erik Hagmark %J Open Journal of Statistics %P 313-318 %@ 2161-7198 %D 2012 %I Scientific Research Publishing %R 10.4236/ojs.2012.23039 %X A new two-parameter count distribution is derived starting with probabilistic arguments around the gamma function and the digamma function. This model is a generalization of the Poisson model with a noteworthy assortment of qualities. For example, the mean is the main model parameter; any possible non-trivial variance or zero probability can be attained by changing the other model parameter; and all distributions are visually natural-shaped. Thus, exact modeling to any degree of over/under-dispersion or zero-inflation/deflation is possible. %K Count Data %K Gamma Function %K Poisson Generalization %K Discretization %K Modeling %K Over/Under-Dispersion %K Zero-Inflation/Deflation %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=20668