We provide a few technical details, additional simulation and empirical results in this supplementary appendices. In particular, supplementary Appendix B provides the discussion on the identification of latent variables and their coefficients. Supplementary Appendix C outlines the detailed MCMC estimation algorithm for the proposed model.We explain the model selection criterion for the latent dimension in supplementary Appendix D. Empirical results from other network relationships and robustness checks of model specifications are reported in supplementary Appendix E. We studies a counterfactual policy simulation to examine the multiplier effects from network interactions in Supplementary Appendix F. The goodness-of-fit of our network formation model to the real data is examined in supplementary Appendix G, while supplementary Appendix H depicts the time evolution of unobserved latent variables.