Appendix A for article ¨From Social Attitudes to Outcomes: The Role of Institutional Quality in Development¨

Structured appendix А contains all supplementary analyses and results referenced throughout the article, supporting complete models transparency, replication, and diagnostic evaluation: i. Appendix A.I – Social Attitude Typology and Network Models. Begins with a country-level table of aggregated social attitude types, derived from 27 ordinal combinations of individual responses, grouped into eight composite categories (e.g., Neg_s, Neu_p, Pos_m). This section also presents results from four network models, estimated via the EBICglasso algorithm within JASP’s Bayesian Network module. While the models are technically undirected partial correlation networks, they are grounded in Bayesian estimation principles, incorporating edge inclusion probabilities, expected influence metrics, and model parsimony penalised via the Extended Bayesian Information Criterion (EBIC). These features place the networks within a Bayesian modelling framework, despite regularisation. The four networks include: Development Outcomes Network Combined Institutional Quality and Development Outcomes Network Development Outcomes with Attitudes (DOA) Network Institutional Quality and Attitudes (IQA) Network Each model includes sparsity measures, centrality scores (strength, closeness, betweenness, expected influence), and graphical figures illustrating key variables and hubs. ii. Appendix A.II – Principal Component Analysis (PCA) contains results from two PCA models based on institutional and development indicators, which inform the selection of latent constructs for Structural Equation Modelling (SEM). iii. Appendix A.III – Multicollinearity Diagnostics Reports VIF analysis results for BTI indicators, identifying multicollinearity risks that may affect SEM stability. The new version contains the corrected Appendix and description Description: Contains full output from two principal component analyses (PCA) used to composit indicators for mediation path analysis. Complements Appendix A.II and supports replication of the component structure discussed therein.