Ethnically fragmented societies choose political institutions that insulate dominant groups.

Evidence

Our interpretation, consistent with our model, is that in more fragmented systems, political systems are chosen to insulate certain groups and prevent others to have a voice. — Philippe Aghion, Alberto Alesina, and Francesco Trebbi, Endogenous Political Institutions, 175

Categorization

• XREF: Connects to literature on ethnic fragmentation and institutional design, e.g. Alesina-style fractionalization work and consociationalism debates.
• SEED: Essay angle: ‘Constitutions as Insulation’ — how electoral rules are engineered to mute rival groups rather than empower them.