Identity voting and social closure: Evidence from Italian municipalities

We examine whether identity-based voting is stronger in socially closed communities. Using municipality-level returns from Italian national elections between 2001 and 2022, we proxy long-run social closure with the share of the most common surname. Higher surname concentration is associated with stronger support for the League after conditioning on municipal characteristics and province fixed effects. The relationship is concentrated in northern Italy and does not extend to Fratelli d’Italia or Alleanza Nazionale. It remains after accounting for civic capital and gender norms, although the data do not identify a unique mechanism. Instrumental-variable estimates based on terrain ruggedness provide complementary, cautiously interpreted evidence.