A new mixture model for capture heterogeneity

We propose a mixture of binomial and beta-binomial distributions for estimating the size of closed populations. The new mixture model is applied to several real capture-recapture data sets and is shown to provide a convenient, objective framework for model selection. The new model is compared with three alternative models in a simulation study, and the results shed light on the general performance of models in this area. The new model provides a robust flexible analysis, which automatically deals with small capture probabilities. Copyright (c) 2008 Royal Statistical Society.