TY - JOUR
T1 - A quasi-likelihood approach for overdispersed binomial data when N is unobserved
AU - Elder, Jennifer A.
AU - Hans Carter, W.
AU - Gennings, Chris
AU - Elswick, R. K.
PY - 1999/6
Y1 - 1999/6
N2 - Several methods for the analysis of binomial data when the denominator, N. is unknown have been developed. Each of these methods requires that the mean of the distribution of N is known. In this article, we develop a quasi-likelihood technique that allows for the estimation of the means of the distributions needed to define the expected value and variance of the observed response and suggest a different form of the variance function. We illustrate the results of the proposed analysis and the results obtained when the mean of the distribution of N is assumed known through the analysis of a surviving jejunal crypt data set. Although the proposed method shows inflated standard errors of the parameter estimates in the cited example, the proposed method performs as well as a previously published method in all simulated conditions. Moreover, in cases where E(N) is misspecified. the proposed method outperforms the previously published method.
AB - Several methods for the analysis of binomial data when the denominator, N. is unknown have been developed. Each of these methods requires that the mean of the distribution of N is known. In this article, we develop a quasi-likelihood technique that allows for the estimation of the means of the distributions needed to define the expected value and variance of the observed response and suggest a different form of the variance function. We illustrate the results of the proposed analysis and the results obtained when the mean of the distribution of N is assumed known through the analysis of a surviving jejunal crypt data set. Although the proposed method shows inflated standard errors of the parameter estimates in the cited example, the proposed method performs as well as a previously published method in all simulated conditions. Moreover, in cases where E(N) is misspecified. the proposed method outperforms the previously published method.
KW - Pseudo-proportional data
UR - http://www.scopus.com/inward/record.url?scp=0041407302&partnerID=8YFLogxK
U2 - 10.2307/1400591
DO - 10.2307/1400591
M3 - Article
AN - SCOPUS:0041407302
SN - 1085-7117
VL - 4
SP - 102
EP - 115
JO - Journal of Agricultural, Biological, and Environmental Statistics
JF - Journal of Agricultural, Biological, and Environmental Statistics
IS - 2
ER -