Paul De Boeck | Searcharxiv

arXiv2021

Heywood cases in unidimensional factor models and item response models for binary data

Heywood cases are known from linear factor analysis literature as variables with communalities larger than 1.00, and in present day factor models, the problem also shows in negative residual variances. For binary data, ordinal factor models can be applied with either delta parameterization or theta parametrization. The former is more common than the latter and can yield Heywood cases when limited information estimation is used. The same problem shows up as nonconvergence cases in theta parameterized factor models and as extremely large discriminations in item response theory (IRT) models. In this study, we explain why the same problem appears in different forms depending on the method of analysis. We first discuss this issue using equations and then illustrate our conclusions using a small simulation study, where all three methods, delta and theta parameterized ordinal factor models (with estimation based on polychoric correlations) and an IRT model (with full information estimation), are used to analyze the same datasets. We also compared the performances of the WLS, WLSMV, and ULS estimators for the ordinal factor models. Finally, we analyze real data with the same three approaches. The results of the simulation study and the analysis of real data confirm the theoretical conclusions.

stat.ME↗

arXiv2021

Joint Latent Space Model for Social Networks with Multivariate Attributes

In many application problems in social, behavioral, and economic sciences, researchers often have data on a social network among a group of individuals along with high dimensional multivariate measurements for each individual. To analyze such networked data structures, we propose a joint Attribute and Person Latent Space Model (APLSM) that summarizes information from the social network and the multiple attribute measurements in a person-attribute joint latent space. We develop a Variational Bayesian Expectation-Maximization estimation algorithm to estimate the posterior distribution of the attribute and person locations in the joint latent space. This methodology allows for effective integration, informative visualization, and prediction of social networks and high dimensional attribute measurements. Using APLSM, we explore the inner workings of the French financial elites based on their social networks and their career, political views, and social status. We observe a division in the social circles of the French elites in accordance with the differences in their individual characteristics.

stat.AP↗