We show how the rootogram - a graphical tool associated with the work of J. W. Tukey and originally used for assessing goodness of fit of univariate distributions - can help to diagnose and treat issues such as overdispersion and/or excess zeros in regression models for count data. Two empirical...

The rootogram is a graphical tool associated with the work of J. W. Tukey that was originally used for assessing goodness of t of univariate distributions. Here we show that rootograms are also useful for diagnosing and treating issues such as overdispersion and/or excess zeros in regression...

Feed-in tariffs under the Renewable Energy Sources Act, the so-called Erneuerbare-Energien-Gesetz (EEG), have triggered a massive expansion of electricity from renewable energy sources in Germany over the last decade. The increase in non-competitive renewable power generation though went hand in...