How Tunisian Polarization Dampened Egypt’s Islamist Rift After 2013 Coup

Understanding the effect of international social ties on domestic ideological polarization is challenging because the counterfactual—what would have happened without cross-border links—cannot be directly observed. This study uses a new statistical approach to estimate that missing comparison and separate polarization into domestic and transnational components following the Arab Uprisings.

📊 Twitter Data From Egypt and Tunisia in 2013

A dataset of Twitter accounts in Egypt and Tunisia was assembled for the critical year 2013, when the Egyptian military overthrew Islamist President Mohamed Morsi.

🔬 A Bayesian Item-Response Approach to Isolate Cross-Border Effects

A Bayesian item-response theory model is applied to disaggregate observed polarization into domestic and transnational components, providing an estimate of polarization both with and without international social connections.

📈 Key Findings

• Following the 2013 coup, retweets among Egyptian ideological allies increased by 50% each day, while cross-ideological retweets decreased by 25%.
• Tunisian Twitter communities also showed stronger intragroup retweeting after the coup, though at lower levels than in Egypt.
• Counterintuitively, the model indicates that the additional polarization in Tunisia after the coup appears to have dampened further polarization among Islamists in Egypt.

❗️ Why It Matters

These results show that transnational social ties can both amplify and attenuate domestic polarization in moments of political crisis. Identifying and measuring those cross-border effects requires methods that separate domestic dynamics from international influence—an essential consideration for scholars and policymakers studying polarization around uprisings and coups.