# Modelling Diffusion through Statistical Network Analysis: A Simulation Study

## TL;DR

This paper introduces a statistical network approach using the Stochastic Actor-Oriented Model (SAOM) to better understand diffusion processes of categorical features among countries, offering advantages over traditional spatial econometric models.

## Contribution

It proposes using a network-based model for diffusion with binary outcomes, improving the specification and inclusion of temporal dynamics and interdependencies.

## Key findings

- SAOM accurately recovers spatial parameters in simulations.
- The model effectively analyzes diffusion of policies like same-sex marriage.
- Network approach simplifies modeling complex interdependencies.

## Abstract

The study of international relations by definition deals with interdependencies among countries. One form of interdependence between countries is the diffusion of country-level features, such as policies, political regimes, or conflict. In these studies, the outcome variable tends to be categorical, and the primary concern is the clustering of the outcome variable among connected countries. Statistically, such clustering is studied with spatial econometric models. This paper instead proposes the use of a statistical network approach to model diffusion with a binary outcome variable. Using statistical network instead of spatial econometric models allows for a more natural specification of the diffusion process, assuming autocorrelation in the outcomes rather than the corresponding latent variable, and it simplifies the inclusion of temporal dynamics, higher level interdependencies and interactions between network ties and country-level features. In our simulations, the performance of the Stochastic Actor-Oriented Model (SAOM) estimator is evaluated. Our simulation results show that spatial parameters and coefficients on additional covariates in a static binary spatial autoregressive model are accurately recovered when using SAOM, albeit on a different scale. To demonstrate the use of this model, the paper applies the model to the international diffusion of same-sex marriage.