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S. R. Hu, C. S. Li and C. K. Lee, “Assessing Casualty Risk of Railroad-Grade Crossing Crashes Using ZeroIn?ated Poisson Models,” Journal of Transportation Engineering-ASCE, Vol. 137, No. 8, 2011, pp. 527-536. doi:10.1061/(ASCE)TE.1943-5436.0000243

has been cited by the following article:

• TITLE: A Comparison of Two Test Statistics for Poisson Overdispersion/Underdispersion

  AUTHORS: Hongyue Wang, Changyong Feng, Xinming Tu, Jeanne Kowalski

  KEYWORDS: Poisson Distribution; Over-Dispersion; Asymptotic Relative Efficiency

  JOURNAL NAME: Applied Mathematics, Vol.3 No.7, June 21, 2012

  ABSTRACT: Within the family of zero-inflated Poisson distributions, the data has Poisson distribution if any only if the mean equals the variance. In this paper we compare two closely related test statistics constructed based on this idea. Our results show that although these two tests are asymptotically equivalent under the null hypothesis and are equally efficient, one test is always more efficient than the other one for small and medium sample sizes.