Title: Hyperparameters of Empirical Bayes Priors for MCMC Estimation of the Multivariate Social Relations Model Authors: Aditi Manoj Bhangale, Terrence D. Jorgensen Abstract: The social relations model (SRM) is a linear random-effects model applied to examine multivariate dyadic data (e.g., round-robin data) within social networks. Such data have a unique nesting structure in that dyads are cross-classified within individuals who may be nested within different social networks. The SRM decomposes perceptual measures into multiple individual-level random effects (incoming and outgoing effects) and dyad-level residuals (relationship effects), the associations among which are often of theoretical interest. Nestler (2018) proposed maximum likelihood (ML) estimation to estimate multivariate SRMs. However, Bayesian approaches, such as Markov chain Monte Carlo (MCMC) estimators, may provide some practical advantages to estimate complex or analytically intractable models. A previous simulation showed that the accuracy of MCMC was greatly dependent on prior information. In this study, we (1) explore the use of ANOVA-based method-of-moments estimation of bivariate SRM relations to compute hyperparameters for empirical Bayes prior distributions and (2) assess the impact of manipulating the precision of these prior distributions when estimating multivariate relations between SRM components with MCMC. We perform a simulation to compare the accuracy and efficiency of ML and MCMC point (and interval) estimates of a trivariate SRM on normally distributed, complete round-robin data. Keywords: Social-network data, social relations model, maximum likelihood estimation, Markov chain Monte Carlo estimation, empirical Bayes priors