Chung, Yeojin; Rabe-Hesketh, Sophia; Dorie, Vincent; … - In: Psychometrika 78 (2013) 4, pp. 685-709
Group-level variance estimates of zero often arise when fitting multilevel or hierarchical linear models, especially … penalized likelihood approach to avoid such boundary estimates. This approach is equivalent to estimating variance parameters by … shape parameter greater than 1, we ensure that the estimated variance will be positive. We suggest a default log-gamma(2,λ …