Current address: Institute of Mathematics and Statistics, University of Kent at Canterbury, Canterbury, Kent CT2 7NF, U.K. email:M.S.email@example.com
A Score Test for Testing a Zero-Inflated Poisson Regression Model Against Zero-Inflated Negative Binomial Alternatives
Article first published online: 24 MAY 2004
Volume 57, Issue 1, pages 219–223, March 2001
How to Cite
Ridout, M., Hinde, J. and DeméAtrio, C. G. B. (2001), A Score Test for Testing a Zero-Inflated Poisson Regression Model Against Zero-Inflated Negative Binomial Alternatives. Biometrics, 57: 219–223. doi: 10.1111/j.0006-341X.2001.00219.x
- Issue published online: 24 MAY 2004
- Article first published online: 24 MAY 2004
- Received August 1999. Revised May 2000. Accepted May 2000.
- Count data;
- Negative binomial;
- Poisson regression model;
- Score test;
- Zero inflation
Summary. Count data often show a higher incidence of zero counts than would be expected if the data were Poisson distributed. Zero-inflated Poisson regression models are a useful class of models for such data, but parameter estimates may be seriously biased if the nonzero counts are overdispersed in relation to the Poisson distribution. We therefore provide a score test for testing zero-inflated Poisson regression models against zero-inflated negative binomial alternatives.