Xu, Dengke; Zhang, Zhongzhan; Wu, Liucang - In: Journal of Applied Statistics 41 (2014) 11, pp. 2504-2514
Efficient estimation of the regression coefficients in longitudinal data analysis requires a correct specification of the covariance structure. If misspecification occurs, it may lead to inefficient or biased estimators of parameters in the mean. One of the most commonly used methods for...