excess coefficient

The "kurtosis excess" is defined in terms of the usual kurtosis by γ_2 | congruent | β_2 - 3 | = | μ_4/μ_2^2 - 3. It is commonly denoted γ_2 or b_2. Kurtosis excess is commonly used because γ_2 of a normal distribution is equal to 0, while the kurtosis proper is equal to 3. Unfortunately, Abramowitz and Stegun confusingly refer to β_2 as the "excess or kurtosis."

central moment | excess | k-statistic | kurtosis | mean | skewness | standard deviation