The literature on the nationalization of electoral politics focuses on the institutional characteristics of political regimes and the structure and organization of social cleavages. We argue that the nationalization of electoral politics is also driven by economic performance. Short-term economic perturbations increase vote transfers from large (and highly nationalized) parties to small (and weakly nationalized) parties. On the contrary, sharp improvements in economic performance may generate vote shifts towards large parties, and then nationalization should increase. Permissive electoral systems exacerbate the influence of economic performance on nationalization. Pooled cross-sectional time-series regression analysis is conducted on data from 43 countries and 475 elections between 1950 and 2012. The party-level mechanisms are shown through a closer look at Austria and Portugal.