Electoral spillovers in an intertwined world: Brexit effects on the 2016 Spanish vote

The Brexit vote took place three days before the June 26, 2016, Spain’s parliamentary elections, in which anti-systemic parties performed worse compared to the previous elections (December 2015) despite the optimistic predictions of the pre-election polls and the surge in the support for anti-systemic parties that was taking place elsewhere (Hobolt and de Vries 2016). We split the Spanish votes in local ones (casted after Brexit) and postal ones (casted before Brexit) and –by employing a differences-in-differences model a la Montalvo (2011)— we provide causal evidence suggesting that the electoral performance of the anti-systemic parties deteriorated due to the uncertainty and fear of destabilization caused to the Spanish electorate by the Brexit vote.