Articles |
Semiparametric model-based inference in the presence of missing responses
Academy of Mathematics and Systems Science, Chinese Academy of Science, Beijing 100080, China qhwang{at}amss.ac.cn jackdpj{at}yahoo.com.cn
Received for publication 1 June 2007.
Revision received 1 January 2008.
| Abstract |
|---|
We consider a semiparametric model that parameterizes the conditional density of the response, given covariates, but allows the marginal distribution of the covariates to be completely arbitrary. Responses may be missing. A likelihood-based imputation estimator and a semi-empirical-likelihood-based estimator for the parameter vector describing the conditional density are defined and proved to be asymptotically normal. Semi-empirical loglikelihood functions for the parameter vector and the response mean are derived. It is shown that the two semi-empirical loglikelihood functions are distributed asymptotically as weighted
2 and scaled
2, respectively.
Key Words: Asymptotic efficiency Missing response Multiple imputation Semi-empirical likelihood Auxiliary information Asymptotic Normality