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A Bayesian analysis of a conception modelChowdhury, Mohammed January 2008 (has links)
Fecundability is regarded as one of the important parameters of fertility performance of the married women. Due to the complex nature of fecundability, we have attempted to estimate mean fecundability from the first conception interval. The first conception intervals have been obtained utilizing the data extracted from the 1999-2000 Bangladesh Demographic and Health Survey(BDHS). The purpose of the study is to estimate mean fecundability by various classical and non classical methods of estimation. Since the cohort of women is not homogeneous, we have attempted to estimate the mean natural fecundability from the Beta Distribution with parameters a and b. For the classical method, the parameters are estimated by the method of moments and method of maximum likelihood. For the non classical methods, standard, hierarchical, and empirical Bayes were used to estimate the mean fecundability. By using the Bangladesh Demographic and Health Survey(1999-2000) Data, the mean conception delay of the Bangladeshi women has been found to be 21.31 months after their first marriage and mean fecundability is 0.04692. This mean fecundability is computed as the reciprocal of mean conception delay. The theoretical arithmetic mean fecundabilities were found to be 0.058 and 0.066 employing the method of moments and method of maximum likelihood. The standard Bayes estimate of fecundability is 0.04696 while the Hierarchical and Empirical Bayes estimate of fecundability are 0.04694 and 0.04692. To compute the Hierarchical Bayes estimate, we used the Gibbs Sampler technique. In the case of Hierarchical Bayes method, we model the prior in terms of another random variable but in Empirical Bayes method, we estimate the parameter instead of attempting to model the parameter from the data. In this study, we have observed that the variation in mean fecundability is negligible whatever the methods of estimation be. / Department of Mathematical Sciences
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